said by dave:Assume you don't have backups:
Large hammer:
Create a new user identity, log in to it, copy all files out of the old account, and blow it away.
Smaller hammer:
Create a new user identity, log in to it, and start doing surgery on the old account: e.g., deleting registry entries that apply to the doomed user. Repeat until you can successfully log in to the damaged account. (Assumes you know your way around enough to do that).
thx
hmmm what sucks is that I will need to reinstal and set up many software and settings and etc.. I wish there way a way to just roll back :/