Windows 2000 Explorer Crash

My os is windows2000. When clicking on the Windows Explorer button, or My Computer, Search, and Settings, the following error message appears “explorer.exe has generated errors and will be closed by Windows. You will need to restart the program. Anerror log is being created”.Although I have downloaded service pack SR4,the problem cannot be solved. I tried to repair from the windows 2000 installation cd but no different.My current version of Norton AntiVirus with updated virus definition detected no viruses.But I can access all files and folders using internet explorer(IE) instead of explorer.My IE version is 5.5. there something that can solve this problem without having to reinstall Windows2000 and having to re-install all the programs.
Thank you for your help,