Windows 7 : auto logoff permantly after login

My university has an application that students must run it to do test (midterm, final,...). It really annoy to all students. It will close all file it can close on computer. (system file too...). So, users must turn account control to default level so... this app cannot auto close it.
I don't know this before. My account control is lowest level. So, when run this app, it will automatically restart. (because some system file has been closed). After twice times, I login at meet that error : No matter how I login, Windows appear Welcome, and logoff permantly after.
When I create another account and set account control to default level, I can run this app and can logon.
But I still want to use old account. (many settings I have set before). Please help me
Thanks :)

From what you say, it would appear your old user profile is corrupted for some reason.

Have a look at this Microsoft article, which offers advice on fixing the problem.

Fix a corrupted user profile

@seavixen7 I have done this many times before. But I do opposite: I copy Ntuser.dat Ntuser.dat.log Ntuser.ini from fresh account to old account. (and of course, all setting will be lost, but data will be no change--> It's more important to me)

But, this time, I have do this and nothing change. Maybe some other wrong with my account. Please help me.