It doesn't by any chance end up as a blank white screen after you enter your login details does it?....and you're using XP?
If so, your XP user profile is corrupt. You would need to create a new user account, and copy everything from "Documents and Settings/old user/ " to "documents and settings/new user" except the "NTUSER.DAT" and "NTUSER.DAT.LOG" files................You would need to do the copy from a third user account with admin privileges....