Window would not start after logging on

Hello, I tried to download a acrobat software but it came - up with lot of trojans and spyware's. I shut down the computer and restarted it again. Everthing booted up perfect. After couple of hours i tried to start the computer but it is not starting up. It start up in safe mood but when i try to start it in normal mode it go up to the log in screen but when i type password system go to welcome messge for couple of minutes and after that screen go black and it does not start the window

Any idea to sort out the problem please.

Thanks

ZIG