Laptop screen turns black when I turn it on?

Okay, so yesterday I tried turning on my laptop and it started loading like normal but when it got to where I login on my windows account thing, the screen turned black with a cursor. What is going on and what can I do to fix it? Btw, I have windows 7 if that helps.

Assuming your battery is charged, press the F8 key right after you hear your computer beep and boot into safe mode. If you can see the screen that way, you can then use the System Restore feature to set it back to a date before the problem started.

If it does that same thing in Safe mode, you have either a virus or a hardware problem.