Windows Explorer disappear

Configuration:
==============
OS: Windows 2000 with SP2
Office 2000 withSP2

Problem:
========
we have a new problem the user can not open Windows Explorer. (it is being closed immediately)

every time he tries by rightclick Start, Explore the Windows Explorer will beclosed immediately.
also when we tried with creating a new Windows Explorer shortcut we get the
same problem.

the only way the user can use Windows Explorer is through opening “My Document”

Is this problem known to you?
what are the next step we should take to solve this problem

we reinstalled SP2 of Windows2000 but without any success.

best regards,
Raoul