Windows 2000 explorer

I have been having problems opening windows explorer. When I open it it takes a while to open up and if I select my computer it will show the drives, but if I select one of the drives the program closes out. It will keep doing this until finally it will open and I don’t know what I am doing to get it open. By this I mean that it will let me open what is on the CD or my documents, but not the drives. When I do finally get it to work it will work until I reboot. What can I do to remedy this problem?