I know is REALLY late to post this (almost 3 years late), but i just found the solution to most of "explorer crashing" issues.
First, run the Windows Repair console (or whatever it is called, im running Windows XP in Spanish so i dont remember how it is called in english) from the CD.
There, you'll be asked to choose one system folder instance to login as administrator. If it doesnt have a password, just press Enter.
When you get to the "C:\" line, write MAP to see which drive letter has your Windows CD. type "X:" (where X is the letter of your CD/DVD drive) and press enter.
There, type "cd i386" and you'll access the X:\i386 folder. Now, type "expand explorer.ex_ C:\windows" and overwrite your old "explorer".
Type exit, and hit Enter.
That should get rid of your Explorer issues, because you'll be using the original explorer that came with your Windows Install.
You can use this same method to fix WinLogon.exe when it's damaged, just replace "explorer.ex_" with "winlogon.ex_"; but you have to use C:\Windows\system32 instead of C:\windows.
Sorry 'bout my bad english, but it is not my native language.