Salvage the Files You Lost From Your Hard Drive

For better or worse, it takes effort to truly delete files from your system. In most cases, files removed from a hard drive actually remain there until new files overwrite them. If a data-recovery program can find the files before they're overwritten, you have an excellent chance of restoring your data.

Whether a file was deleted accidentally or is inaccessible because of damage to the drive or its file system, remember the golden rule of data recovery: Act fast! The more you use a hard drive, the more likely the file will be overwritten and lost forever.

Undo a deletion: Files that have been "permanently" deleted--when you empty the Recycle Bin or press - to bypass the Recycle Bin entirely--aren't really deleted; Windows just alters each file name's first letter in the disk's bookkeeping system so the file will be ignored by the operating system. Windows tags as available all the space each file is using on the disk, designating the file as overwritable. Recovering a deleted file is therefore a matter of having a tool that restores the file's original name and retags the file before Windows or one of your applications overwrites it.

Symantec's $70 SystemWorks 2005includes an undelete program, and the free trial version of Ontrack's $89 EasyRecovery Lite 6will tell you whether a file is recoverable (see FIGURE 1

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Figure 1: Recover files erased from your hard disk with an undelete utility such as Ontrack's $89 EasyRecovery Lite.
). A free alternative is Brian Kato's Restoration utility).

If you use Windows XP or 2000, make sure the program you select supports the file system your hard disk uses, either FAT32 or NTFS (read on for more on Windows file-system differences). If you're not sure which format your hard drive uses, open My Computer, right-click the drive's icon, select Properties, and look to the right of 'File system'.

Repair damaged files: When you format a hard drive--or more accurately, a partition on a hard drive--you create the index that locates each file on the drive. Windows 98 and Me use the FAT or FAT32 file systems. Windows XP and 2000 use either FAT32 or NT File System (NTFS).

This index is known as the File Allocation Table (FAT) in FAT32 and the Master File Table (MFT) in NTFS. If either is damaged by a virus or completely overwritten by formatting of the drive, Windows has no way to locate the drive's files.

A data-recovery program may restore your FAT or MFT from backup copies, or reconstruct the index. If the index can't be fixed, however, a good recovery program will still be able to scan the drive to identify and recover some of its lost files.

Norton Disk Doctor in SystemWorks, the Scandisk application in Windows 98, and the Chkdsk program in all Windows versions identify bad sectors on your hard disks and move data to a healthy sector, but these utilities don't recover much data. I've had more success resuscitating lost files using EasyRecovery.

This program scans for files matching its database of 90 common file signatures. It can recover some or all of the files it identifies. EasyRecovery also fixes--or at least partially recovers--inaccessible Word documents and.zip files.

EasyRecovery Lite limits you to only 25 recovered files per session--but the program lets you run as many sessions as you need. The standard version, EasyRecovery DataRecovery, sells for $195 and lets you recover all the files you want in one session, but otherwise the two versions offer about the same features.

Power-Hungry Hubs

Do your PC's USB ports supply enough electricity to power all the devices you have attached to them? Plugging too much gear into a bus-powered USB hub (one with no external power adapter) can overwhelm a USB port by demanding more than the 500 mA it can supply. Check the power demands on any USB port in Windows XP by right-clicking My Computer and choosing Properties, Hardware, Device Manager. Double-click Universal Serial Bus controllers, double-click the USB Root Hub entry, choose the Power tab, and add up the amounts in the 'Power Required' column.