ANOTHER FIX FOR LOST GRAPHIC FILE PREVIEW IN WIN9X
If you're the type that likes to get into the Registry and fix it yourself (the hard way), I have something for you. My good buddy Bob H recently posted a fix by TipWorld. Here's what to do:

• Launch Regedit.
• Go to HKEY_CLASSES_ROOT\ and look for the type of file you want to preview, such as .gif. With that key selected, press the * (asterisk) key on your numeric keypad to expand all keys within it.
• In order for preview feature to work for that file type, the following entries must be there:
  • Registry Key: HKEY_CLASSES_ROOT\\ShellEx
  • Registry Key:
    HKEY_CLASSES_ROOT\type\ShellEx\{BB2E617C-0920-11d1-9A0B-00C04FC2D6C1}
  • Value: (Default) = "{7376D660-C583-11d0-A3A5-00C04FD706EC}"
• If any or all of these entries aren't there, you'll need to create them, as follows:
  • Right-click HKEY_CLASSES_ROOT\, select New and then Key and type ShellEx and press Enter.
  • Right-click the new ShellEx key, select New then Key and type {BB2E617C-0920-11d1-9A0B-00C04FC2D6C1} and press Enter.
  • With the newly created key selected, right-click (Default) in the right pane and select Modify.
  • On the Value Data line of the Edit String dialog box, type {7376D660-C583-11d0-A3A5-00C04FD706EC} and click OK.
• Enjoy!

FIX MISSING TASKBAR IN WIN98 OR WINNT
If you suddenly find that your taskbar is missing from Win9x (or NT) ...

• Launch Regedit.
• Back up your Registry.
• Drill down to
  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\StuckRects
  and export that key to a safe place.
• Once you've verified that your export worked and that the REG file is complete and correct (so you can undo the change you're about to make), go ahead and delete it.
• Reboot.
• Enjoy!

RESOLVE THE "FLOPPY SEEK" ANNOYANCE IN WINDOWS EXPLORER
When launching Windows Explorer for the first time after booting Win98, you are delayed about two or three seconds while Windows searches your floppy drive looking for a disk. You can change all that quite easily:

• Launch Regedit and drill down to
  HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
  and look for a DWORD whose value is "NoDriveTypeAutoRun"=dword:00000091.
• If the value is there and you'd like to stop this behavior you can delete it. However, it is always prudent to back up any value you delete (or alter) by first saving or exporting it to a REG file.
• To do so, just highlight the DWORD value and then choose the Registry pull down menu and then click the Export Registry File... item. Type a name you will remember and save it in an easy to get at place. If you don't like the results of the modification, you can undo the changes by simply double clicking the REG file in Windows Explorer. The deleted DWORD value will be replaced as if never gone.
• This Registry modification should also allow you to disable autorun for DATA CDs.
• Enjoy!