I use a Dell Vista laptop Inspirion 1525. It has worked very well until recently when it worked at 6 AM and by noon was not functioWindowning well. After the Dell splash screen it goes to a black and gray screen. The words windows Vista is at the top and at the bottom are the words memory diagnostics. Running the diagnostics does nothing. I ran Avast and the diagnostics available with the F12 key. Nothing showed up. Finally I figured out that if I selected Windows Vista and pressed Enter, the computer would proceed to open and work mostly normally. I submitted the situation to some repair sites and got the opinion that it was a virus but no one could say what virus or what to do about it.
Can anyone here help me? Is it a virus? If so, what can I do about it?