6 Data Recovery Tools for SD Cards, USB Drives and More
As USB thumb drives and memory cards get larger and cheaper, it's getting easier to trust much more of your data to them. It's also much easier to mistakenly erase data or have them hiccup on you. And if you're in the habit of holding on to that data for too long -- for example, not transferring photos from your camera's memory card -- disaster is almost guaranteed to strike at some point. What happens then?
While there's no end of data recovery software packages out there, most of them are primarily designed to reclaim data from system drives. In this roundup, I look at the following six packages in terms of how well they recover data from mobile storage such as flash drives and memory cards: CardRecovery, PhotoRec, Recover My Files, Recuva, Remo Recover and Undelete 360.
Mobile storage devices can pose their own challenges for data recovery tools. A damaged device with no proper partition data might not mount correctly, making it impossible to use with tools that require a drive letter. Memory cards used in cameras can have data stored on them in oddball formats, such as Canon's CR2 raw-image format, a custom variant of the TIF format.
How We Tested
For testing, I used two storage devices: a Transcend 8GB SDHC card (Class 6) and an 8GB Kingston DataTraveler flash drive. Both were formatted as FAT32 and loaded with 5.8GB of files, a mixture of image files in multiple formats (JPG, GIF, PNG, Photoshop), audio files (variable bit-rate MP3), Microsoft Office documents, ZIP archives and PDF files.
I tested them using the Windows versions of these recovery apps. (Some of these products also offer versions for other platforms, which I didn't test; these are noted at the top of each review.) Tests involved selectively erasing and recovering files, and attempting to recover all files after a quick format (one where only the directory information is erased, not each block on the disk).
OS: Windows 98 and later. (CardRescue available for Mac OS X)
CardRecovery is the most focused of the applications reviewed here: It exists mainly to recover files from memory cards used in cameras. The only file types it works with are JPG and RAW-format image files, and video and audio files (e.g., AVI, MPG, MOV, MP3, WAV). It will not search for documents, archive formats, some image formats (such as Photoshop or PNG) and other day-to-day file types.
On the plus side, CardRecovery offered the best detection of CR2 files I found. In addition, its wizard interface made the recovery process quite easy. To begin a scan, just enter a drive letter, a camera brand (optional) and/or a file type (also optional), and a destination folder in which to save the recovered files.
The results of the scan are shown incrementally, although there's no preview mode during the scan, which makes it harder to tell if a given file is in fact what you're looking for without stopping the scan. A full scan of each of my 8GB devices took just under 10 minutes.
Once the scan's complete, you can preview JPGs (but only JPGs) and the program window can't be resized, so you can't ever see more than six thumbnails on the screen at once. This makes it a little harder to deal with RAW-format files, especially since file names aren't recovered: It might be easier to just recover everything and sort it out later.
Because CardRecovery can only work with devices that have a drive letter, it may not be of much use if you're dealing with a card whose partition information is damaged and therefore can't be assigned a drive letter. (PhotoRec, in contrast, can work with any device even if there's no partition data.)
CardRecovery offers a free trial version that will scan media and find lost files, but you must buy the full version to recover them.
If quickly recovering data from cameras is a priority, CardRecovery might be well worth the $40. Since the trial version allows you to preview recovered files, you can try that first to see if it suits your needs.
Best practices for recovering data from mobile drives
Restoring data from USB drives and memory sticks comes with some of the same caveats as any other data-restoration effort. Here are a few useful tips:
Use write protection. To prevent further accidental destruction of data, mobile storage devices should be mounted as read-only whenever possible before you attempt any recovery operations. SD cards typically have a write-protect switch, which makes it easier to protect them before attempting a recovery operation. Removable USB drives are a stickier wicket, since Windows does not have a way to manually mount their file systems as read-only. There is a Registry setting that works with Windows XP SP2 and higher; it forces all USB mass-storage devices into read-only mode. (Note that any program that expects the device being recovered to be writable, such as Remo Recover, may balk at this.)
Be patient. If you're using a program that supports deep scanning at the cost of a slower recovery process, use it. The speed of this type of scan depends on your system's CPU rather than its I/O, as most of the work involves matching file signatures and checking for false positives. If you're in a hurry, run a deep scan using the fastest machine you have access to.
Remember to use the "Safely Unplug Hardware" option. Memory cards and sticks generally tolerate immediate removal, but do yourself a favor and remember to safely eject these devices before removing them, just to be sure. This cuts down on the possibility that data will be lost in the first place.
Next Page: Photo Rec, Recover My Files, Recuva...
OS: DOS, Windows 98 and later, Mac OS X, Linux (2.4 /2.6 kernel)
In some ways, PhotoRec is the most powerful application in this review. It can recover files from almost any device -- whether or not it's mounted with a drive letter, has a partition or is even formatted. PhotoRec has editions for multiple platforms: Windows, Linux and Mac OS X. And its creator claims it can detect and recover more than 390 types of files, and not just photos, as the name might imply. However, its very Spartan interface may be off-putting to users who expect a slick graphic interface.
When you launch PhotoRec, you're given a list of all the available storage devices in the system: hard drives, attached removable drives or loaded card bays -- but not networked drives. Choose a device and a partition, set your search options (the defaults work fine for basic recovery), pick a place to save the recovered files to and the rest is pretty automatic.
A recovery pass can be halted and resumed later if need be, especially if the time estimate for recovery (which is gratifyingly accurate) runs into hours. A full scan of each of my 8GB devices only took about 10 minutes, although the "unformat" option (see below) easily doubled that.
Recovery searches can be performed on either the space marked as free or on the entire drive, regardless of what files already exist. One feature that goes hand in hand with this is the "unformat" function, which analyzes the entire drive for file system structures instead of simply looking block-by-block for valid files. This is useful if you want to recover directories instead of just files (although for the most part I was happy just to get the files back).
It's even possible to recover from a device whose partitions have been damaged or which has bad directory information. You can also add your own custom file types to the program if you're looking for files that aren't in PhotoRec's dictionary of signatures.
PhotoRec restored everything I was looking for, although file names weren't recovered and CR2 files weren't saved unless I enabled an expert option to save "broken" files (possibly because they were seen as damaged TIF files). Also, even though PhotoRec runs on Windows, don't expect a GUI: it has a command-line interface.
You also need to pay close attention to each of the available menu choices, since some of the most crucial options are not obvious. Finally, the online documentation isn't what it could be -- options like the FAT32 unformat command, for instance, aren't clearly explained there.
The lack of a graphical user interface for PhotoRec may be intimidating for some, but the sheer power and flexibility of the program can't be denied. I recommend that advanced users start here; they won't regret the extra effort needed to make the most of the program.
Price: $69.95 (Standard); $99.95 (Pro); $299 (Technician). Free trial available (only previews files)
OS: Windows 98 and later
Recover My Files comes in a few different iterations. The version I reviewed ($69.95) helps you recover a variety of file types from conventional FAT/NTFS partitions; there are also Pro ($99.95) and Technician ($299) versions that both add HFS and RAID support. The Technician version also includes a USB hardware dongle that activates the software. If you only need to restore image files, GetData also offers a $39.95 app called Recover My Photos.
On startup, Recover My files gives you two choices: recover individual files or recover files from a whole drive (for example, one with damaged partitions). The former simply scans directory structures for evidence of deleted files; the latter deep-scans the whole file system and attempts to reconstruct lost partitions or directory structures.
What's great about the deep scan is it's tunable. The default version of the scan looks for common file types such as images, documents and music. The most intense scan runs more slowly and may turn up more false positives, but it tries to match a much broader -- albeit less widely used -- range of file types, such as database files or fonts. If you want, you can speed up the search by concentrating on specific file types if you know what you're looking for. (There's a version of this same feature in PhotoRec, but it's made a lot more accessible here.)
Files found during the scan will show up in a directory tree, with previews if available, on the left side of the application window. If the files you're looking for show up early in the process, you can abort the scan and just recover what you need. A "Search" tab also lets you ferret out files by various criteria, including data inside a given file such as a key phrase.
Once you've tagged the files to be recovered, they can be saved to any other device, with issues that came up during the save (path names being too long, files automatically renamed because of collisions, etc.) tabulated at the end.
It took 9 minutes and 18 seconds to scan my 8GB memory card and flash drive, but that was with only the most basic file-recovery options enabled. If I wanted to recover my CR2 files, I needed to widen the search to include those, because the CR2 format wasn't in the default file set. That scan took about 18 minutes. Scanning for all possible file types supported by the program slowed the search down to 2 hours, 18 minutes (so you can see how a focused scan saves time).
The high price tag for GetData's Recover My Files is a bit off-putting, but the program did an admirable job of scouring and recovering files from my test media -- as long as you don't mind being patient while waiting for the best possible results.
Price: Free; home ($24.95) and business ($34.95) support available
OS: Windows XP and later
Say the name out loud: It's pronounced like "recover" -- which is exactly what this snappy little program does, and in a highly automated way. The free version of Recuva is full-featured but doesn't include any type of support. Piriform sells support to home users for $24.95, and it offers a business-support license for $34.95.
When first launched, Recuva starts in wizard mode, which prompts you with basic questions about what you're trying to restore -- a specific type of file, a specific drive, or even a specific type of drive -- and then gets to work. It took about 10 minutes to scan my 8GB card and I was able to run the scan unobtrusively in the background.
After the scan, Recuva presents you with a very detailed breakdown of what files were found. Click on any file and you'll be given detailed information about it -- how healthy the file was (i.e., whether or not it was partly overwritten), a hex dump of its header information, and even a preview for certain supported file types such as JPGs. Files to be recovered can also be browsed as thumbnails, which is handy if you're looking for one image among many. Note that file names are generally not recovered; the resulting files are given arbitrary names and have to be renamed manually.
Advanced options allow you to recover files that haven't been deleted -- e.g., from damaged drives -- or to try to restore the original folder structure of the source media. Recuva can also securely erase files found during a recovery operation, a handy way to make sure a given file has been properly destroyed if you're concerned about security.
All the test files I looked for were recovered, although Recuva interpreted my CR2 files as TIF images. It still recovered them properly, though, and they were fine once renamed.
The wizard-guided interface for Recuva makes the recovery process a snap. The quality of the program's file recovery and the price (free) make it a solid choice for the average Windows user.
Next Page: Remo Recover, Undelete 360, Conclusions...
Price: $39 (Basic); $49 (Media); $99 (Pro). Free trial available (only previews files)
OS: Windows 98 and later. Versions available for Mac OS X.
A close cousin to Recover My Files in terms of functionality, Remo Recover comes in three versions for Windows, depending on how much of a recovery you need to perform. The Basic Edition ($39) does simple file recovery, the Media Edition ($49) can recover RAW format photos, and the Pro Edition ($99) recovers files from lost partitions or reformatted drives. All the versions are contained in the same download and simply require different unlock codes, so I tried all three.
(Mac users can also find the same breakdown of editions and usability for slightly different prices: $59 for the Basic Edition, $69 for the Media Edition and $179 for the Pro Edition.)
No matter which version you've purchased, the opening menu lets you start a search based on the type of recovery needed; if you try to do a recovery type that's only available on a version you haven't purchased, you'll get a demo mode that allows a preview of what's to be recovered.
As with Recover My Files, you can choose which specific files to perform a deep scan for, as a way to narrow the search. Unlike that application, though, Remo Recover doesn't display the search results incrementally -- you have to wait for the whole scan to finish before you can choose what to salvage -- and there isn't the same kind of "common file format" selection choice.
That said, searching for all the known formats in Remo Recover was faster than the same search in Recover My Files: It took 15 minutes instead of over an hour. Recovery sessions can also be saved and resumed later.
One possible drawback to the way Remo Recover searches for files was the high rate of false positives, or wrong file type assignments, that turned up in my sample. I ended up with a great many files labeled ARJ, for instance, even though there were none in that format on the device to start with. (Deselecting ARJ for the search fixed this problem.)
I did like Remo Recover's ability to preview individual files from its lists of recovered files, although the preview only works for a small subset of file types: Images and audio preview fine, but there's no support for Office documents or PDFs.
Be warned that if you write-protect your media as a protection measure during the recovery process, Remo Recover does not deal with that well. During tests, it crashed consistently when I tried to recover data from write-protected devices.
The price, speed of search and breadth of files recovered with Remo Recover all make it a pretty good deal. I wasn't too fond of the rate of false positives, though, which means you need to be as precise as you can about which file types you're looking for. And be careful of recovering from read-only media.
OS: Windows 2000 and later
There's little question Undelete 360 is easy on the eyes: It's got a snappy-looking interface reminiscent of an Office 2007 application. But despite the splashy looks, it's not as self-guiding as Recuva -- and it does a far weaker job of recovering data than the competition.
When launched, Undelete 360 scans the available drives in the system and lets you choose one or more to inspect for deleted files. If it finds anything, it produces a list that can be filtered by file types and properties. Some file types can be previewed (provided the program judges them to be in recoverable condition), and a hex view tab lets experts peek at the file's raw data if they're curious.
I suspect Undelete 360 only scans directory structures and does not perform the kind of intense block-by-block scan used by other products here. To begin with, it returned a list of potentially recoverable files a great deal faster than the competition -- which seemed like a good thing on the face of it, but also implied a superficial search. The program also didn't do as good a job of recovering the files -- half the time, files were reported as "overwritten," even when the very same files were restored by other apps reviewed here.
Worse, Undelete 360 seemed to be just about useless when confronted with a quick-formatted drive. When I performed a quick format on my media and let Undelete 360 scan it, it turned up nothing -- and again, turned up nothing a little too fast for my own comfort. No options appear to exist to force the program to do a deep search for files from the beginning.
There are a few handy features, like the data-wiping tool reminiscent of the one in Recuva and the ability to recover alternate NTFS data streams. But those fall flat in the face of Undelete 360's much larger weaknesses.
A good interface and a nice preview system do not compensate for the program's inability to deal with anything more than recently deleted files.
Undelete 360 worked best when dealing with recently deleted files, but anything more ambitious than that (e.g., quick-formatted media) was beyond it. CardRecovery's biggest limitation was the limited range of file types it handles: It's designed mainly to recover files created by cameras and almost nothing else.
Recover My Files may be costly, but I liked its tunable scan function; its professional-level support for devices like RAID drives may come in handy. Remo Recover is functionally similar to Recover My Files, but it turned up a high number of false positives during testing.
The biggest surprise was how two of the best programs cost nothing to use. While PhotoRec was the least novice-friendly -- its text-only interface could scare off the uninitiated and its documentation is spotty -- it was also one of the most powerful. Recuva was likewise quite strong and wasn't lacking any functionality in its free version.
As a result, I recommend PhotoRec for tech-savvy users and Recuva for everyone else.
Serdar Yegulalp has been writing about computers and information technology for a variety of publications for more than 15 years.