I have the following lines in a DOS script to speed things up, and to save disk space:
del C:\windows\prefetch\ntosboot-*.* /q
del "C:\documents and settings\*\local settings\temporary internet files\content.ie5\*\*.*" /q
del "C:\documents and settings\*\local settings\temporary internet files\content.ie5\*\*" /q
del "C:\documents and settings\*\local settings\temporary internet files\content.ie5\index.dat" /q
del "C:\Windows\Temp\*.*" /q
del "C:\Windows\Temp\*" /q
the first line makes XP boot a lot faster, the others are deleting temporary files
also, to speed up browsing files, you can go to tools, folder options, view, then deselect "automatically search for network folders and printers"
it should locate and display files and folders quicker this way
this doesn't mean you can't use network folders or printers, it just means it doesn't automatically search for them