Very annoying to fix explorer related problems. Make sure you have all the recent windows service packs.. try looking for an explorer fix/repair/replacement install file in microsoft.com.. if all else fails just reinstall windows.
_P4 Northwood 2.8C Ghz HT
_Kingston 512 DDR400 Ram [2x 256]
_Awesome looking white plain case with cool green and red power/HD lights, and a newely acquired Intel P4 sticker!