• PC World
• » Software
• » Utilities

Disk Scanners

Hard drives develop errors, both physical (on the surface of the disk) and logical (in the data itself). A good disk scanner should catch and correct problems of both sorts before they become serious. Ideally, you should perform a quick scan every day to check logical integrity, and a thorough scan every couple of weeks to check for scratches.

No major software company markets a stand-alone disk scanner, but Windows 95, Norton Utilities, and Nuts & Bolts all include scanners of their own. To pick the best, we created three common logical problems on a 2GB hard drive: a corrupted file allocation table (or FAT, which tors available disk clusters and tracks the clusters that contain each file's data); lost or orphaned clusters (available clusters the FAT thinks are in use); and cross-linked files (two files the FAT thinks end in the same sequence of clusters). To test each package's ability to detect physical damage, we pricked a floppy disk with a pin and let the scanners try to salvage the data.

SUMMARY

Disk Doctor (Norton Utilities) PRO: Fast, includes undo feature. CON: Couldn't save file in pinprick test. Symantec 800/441-7234 www.symantec.com

Disk Doctor (part of Norton Utilities) did a good job with major problems, but other programs were better at surface scanning. On the plus side, it's easy to use (though it has goofy animation), fast (a quick scan took 16 seconds and a thorough scan under 6 minutes), and offers a reassuring undo feature. It found and fixed all our logical problems, but in our floppy pinprick test it didn't repair the damaged file and wouldn't let us copy it to the hard drive. It's a good tool, just not the best.

SUMMARY

Disk Minder (Nuts & Bolts) PRO: Best damaged-file repair, fastest. CON: Insufficient reports. Network Associates 408/988-3832 www.nai.com

Nuts & Bolts' Disk Minder is the best utility we found for scanning a hard drive. For one thing, it's the fastest: On the quick scan, Disk Minder took just over 7 seconds--9 faster than Norton's Disk Doctor, and 22 seconds ahead of Windows 95's ScanDisk. And like Disk Doctor, it offers an easy interface and an undo feature. Even better, it's the only disk scanner that passed our pinprick test, letting us copy a damaged file to our hard drive. Our only complaint: Though Disk Minder gives you a detailed error report, it's the only disk scanner that doesn't tell you which file is damaged. Otherwise, it's our fave.

SUMMARY

ScanDisk (Windows 95) PRO: The price is right. CON: Very slow, no undo feature. Microsoft Corp. 800/426-9400 www.microsoft.com

ScanDisk--the disk scanner included as part of Windows 3.x, Windows 95, and NT--is as slow as an eighteen-wheeler in rush-hour traffic. In our tests, a quick scan took just under 30 seconds, but a thorough scan took more than half an hour. You might as well head out for a bite to eat. Once ScanDisk is finished, however, its results are as good as Norton Disk Doctor's. And as with most disk scanners, this one is easy to use. It found every error and fixed them all (except for the pinpricked floppy, that is). Unfortunately, ScanDisk lacks the undo feature that other scanners include. If you're willing to spend a little money, you can do better.