i can not sign into windows messenger,comes up invalid user name password,on trouble shoot says code 80070057,when i go to do a bt mcafee scan it will not open on desk top,then feezes,have to keep turning off,looked up websites for downloading anti virus,but every one stops with 1% to go,and freezes,also on start up it says microsoft needs your permission to continue?which never has done before thanks.


Get Microsoft Security Essentials and scan your computer. Then, just to be safe, scan it with these tools:http://www.f-secure.com/en/web/labs_glob…
Go to safemode,(f8 on startup) then login, and run virus protection. It should work. If not, restart your computer then go into safemode with networking (f8 once again) and install a malwarebytes onto your computer, then just run full scan.
download and install antivir.
start windows in SAFE MODE
(Press F8 while the computer is starting)
make a virus scan.
restart computer.
download and use ccleaner
http://www.chip.de/downloads/CCleaner_16317939.html