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.
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