Sometimes I empty Windows' Recycle Bin before I realize that I shouldn't have deleted a particular file. And if I delete a file through the command line or if the deleted file is too big, the files might never get to the Recycle Bin. How do I get these deleted files back?

Jon Martinez, Cottonwood, Arizona

It's easy to restore a deleted file that's still in the Recycle Bin--just right-click it and choose Restore. But recovering a deleted file that's not in the bin is no sure thing. Luckily, Windows doesn't actually erase the data until it reuses the disk space formerly occupied by the deleted file, so recovering the data is possible.

You can do three things to increase the likelihood of recovering a deleted file:

Back up your data: If you have a copy, you may not have to undelete the original.

Defrag your hard disk often: Restoring a deleted file is more likely if it was on your drive in one contiguous piece.

Don't write to the drive: Avoid saving files or otherwise accessing your hard disk until you have restored the file. Windows treats a deleted file as available space, so saving a new file could overwrite the deleted one, thereby rendering it irretrievable.

That's why I recommend DTI Data's $25 Fast File Undelete, which operates without writing to the hard drive. Download the utility onto another computer, unzip the program file to a floppy disk, insert the floppy in the PC with the deleted file, and run the program. Download the demo (which requires registration and will retrieve only files smaller than 15KB), or visit the company's site to buy the full version.

What's .dat in My E-Mail?

People have received e-mail from me with an attachment named winmail.dat. Is this a virus?

Brian Zoriki, via the Internet

No, it's not. Outlook uses a Microsoft Exchange format called Rich Text that can't be read by other e-mail software--even Outlook Express. When you open an Outlook Rich Text message in another program, you get plain text plus an attachment with a .dat extension--usually named a variation of "winmail.dat". To stop sending Rich Text messages to non-Outlook recipients, click Tools, Options, Mail Format. In Outlook 2000, select Plain Text or HTML, and click OK. In Outlook 2002 and 2003, click the Internet Format button, select Convert to HTML format in the 'Outlook Rich Text options' drop-down menu, and click OK twice.

Control XP's Picture Editor

The button in Windows XP's Picture and Fax Viewer for editing an image [see FIGURE 1] previously opened Photoshop Elements, but since I updated that program, it brings up Microsoft Paint. How do I change this setting?

Joseph A. Lurz Jr., Spring, Texas

You can't change this file association in Windows Explorer. You have to edit the Registry. (See "How Do I Restore My Windows Registry?" for Registry backup instructions first.)

Right-click the Start menu shortcut to the program you want to use to edit your images, and click Properties. Select the path and file name in the Shortcut tab's Target field, and press Ctrl-C to copy it. Click Cancel, and then Start, Run. Type regedit and press Enter. In the Registry Editor's left pane, navigate to and select HKEY_LOCAL_MACHINE\SOFTWARE\Classes\SystemFileAssociations\image\shell\edit\command. In the right pane, double-click the (Default) listing.

Select the first part of the 'Value data' field's contents (something like '%systemroot%\system32\mspaint.exe'). Press Ctrl-V to insert what you copied from the shortcut. Leave the last part of the field contents, '%1', untouched. Click OK and close the Registry Editor.