error-to help protect your computer windows has closed the program.

while pressing ctrl+alt+del give user name & password message shows that- to help protect your computer windows has closed the program.
name - Userinit Logon Application.
publisher - microsoft Corporation.
Followed by button Closed Message,After pressing closed button Tab another message come - Userinit Logon Application has encountered a problem & needs to close.We are sorry for inconvenience.
I can't able to see Desktop & this is not happened with Virus Because after formatting the m/c this problem occured.
Plz suggest me the solution