When a file is deleted or the Recycle Bin is emptied, the data it contains isn’t actually erased. Instead, the space it occupies on the disk or memory card is marked as available for reuse. If you realize your mistake immediately, special undelete software should be able to recover an accidentally deleted file. The longer you leave it, though, the greater the chance that the data will be overwritten, rendering the file lost forever. For this reason, it’s important to act quickly to maximize your chances of success.
The file-recovery software we’ll be using is called Disk Digger. However, don’t download or install it until we indicate how to do so. Disk Digger is shareware, and although it’ll allow you to recover files without registering, you’ll get a nag screen for each file until you pay the $15 fee.
Recovering Files from External Media
1) First we’ll show you how to recover files from external media such as a USB memory stick or your digital camera’s memory card. In this case, it’s perfectly safe to download DiskDigger on to your hard disk. Open your browser, head to diskdigger.org, click Download and Download now, then save the Zip file to your Windows Desktop. Double-click the Zip file and you’ll see two files: license.txt and diskdigger.exe. Rather than installing permanently on your system, DiskDigger runs from this .exe file; double-click it to run it. Depending on which version of Windows you have, or whether you have WinZip or similar software installed, you may be asked to extract or run the file – choose Run.
2) The opening screen shows all the disks, so select the one containing your lost files and click Next. Various options are presented. For now, accept the defaults by clicking on Next again. Your disk is scanned and any deleted files listed; this could take some time. If this works, and several files are found, go to Step 3. If not, click Back and select Dig Deeper. This time, when you click Next, you’re shown more options; we suggest you accept the defaults and click Next.
3) The files found may not be shown with their correct filenames but with partial filenames or sector numbers, such as Sector 109450. This isn’t useful in identifying lost files. DiskDigger provides a means of previewing the lost images or, for other file types, looking at the first few bytes. Select the file in the list on the left and choose the Preview or the ‘First few bytes’ tab. The Thumbnail option in the View menu is also useful; it shows small images in place of the sector numbers in the list. For non-graphic files, if the first few bytes don’t identify your file, you may have to try recovering files speculatively and opening them in the relevant application.
4) Once you’ve identified your missing files, make sure they’re selected in the list on the left and click ‘Save selected files…’ at the top-left of the screen. Hold down Ctrl as you select each sector to choose more than one. In the ‘Browse for Folder’ dialog box, select the folder to which you want to restore the file (this must not be on the same device as the lost file) and click OK. The missing files will be saved with names such as sector546026.JPG, so rename them using more suitable descriptions.
Recovering Files from a Hard Disk
5) If your deleted file is on your hard disk, do not attempt to download DiskDigger on to that disk – it could end up overwriting the file you’re trying to recover. There are two possible solutions to this predicament. The easier, but less reliable solution is to download DiskDigger to a USB memory stick or other external storage device and run it from there. Follow the process described in Steps 2 to 4 – but in Step 2 select the hard disk instead of external media, and in Step 4 choose to save the recovered file to an external device. This last point is crucial – never do anything that will write to your hard disk until you’re sure you’ve got your missing files back.
6) There’s a degree of risk attached to the process described in Step 5, because there’s a chance that an application that’s running – or even Windows itself – will write to the hard disk behind the scenes. The safer option is to switch your PC off at the wall – shutting Windows down will cause any settings to be saved to disk – and then install the disk to another PC as a secondary drive before attempting to recover your files. You should read Advanced Projects, Shopper 269 for advice on installing the hard disk on another PC.