Disk Defragmenter

Unfortunately I have Diskeeper Pro installed, which replaces the Windows defragmenter file and I can't remember the name of the file that opens the Windows defragmenter window.

 

 Maybe someone else can jump in here? Edit: OK Denny already did while I was typing; took longer than usual as IE misbehaved and I had to start over.

 

You could try opening defrag from within help and support: click start, click help and support. In the search box type defrag, click the green arrow. Then in the left pane under suggested topics, click on using disk defragmenter. In the right pane click on open disk defragmenter. Does it open from there? If so it is the short cut that is broken; if not then the file may be missing or corrupted.

In the latter case you could try:
click start, click run, type sfc /scannow  [note space between c and /]; click OK
sfc (system file checker) will run and replace any corrupted or missing system files. Depending on your set up it may ask for your XP CD. It does not report any results.

An alternative method to defragment you could try is the following [I assume that you want to defragment C:\]

Click start, click run, type cmd, click OK.
That opens the command (DOS-like) window. At the > prompt type defrag C: -a   [note spaces between g and C and between : and -]; press enter.

You should get a line giving the analysis report, including % fragmentation, and free disk space.
If that works, and provided that there is adequate free space, and you want to defragment, at the prompt type defrag C:  [note space between g and C]; press enter.

It should first report the analysis again, then start the defragmentation and finally report the result in a line headed Defragmentation Report. This method does not open the usual defrag window. While it is busy defragmenting you just see a blinking -. Be sure to let it finish, do not close the command window while defrag is running;  it may take some time.