My Computer shuts down as soon as I try to type in my computer login password....Why?

I understand your pc is infected by virus.It's copied to starup also.

boot your pc using OS CD.Access into recovery console by selecting 'Repair' option.Then remove all the programs from startup.check the startup program carefully & findout the malicious .exe program.If any malicious .exe found also check this file into System32 folder.Remove from System32.

Then try to access into Safe mode.Hope you will be able to login.Scan your computer by using an anti-virus(updated definition).Restrict malicious files by using 'secpol.msc'

Hope everything will be ok.

Rigan

Rigan.

i know your grief. try this: remove the keys from your keyboard and re-install them randomly. then re-type password and it should work. this solution is based on the presumption that the virus your computer has scrambles up your password as you type.