Windows - Black screen after login - sleep bug?

Hi everybody. I've got XP installed via bootcamp on my macbook pro. When the laptop sits a while, the screen tends to go black, into a sort of sleep mode, and when I want to use it again, the computer emits an internal sound like it's booting up, but then it shows the account/profile login scree. After I log back in, it's just as I left it. This is standard.

Tonight, I came back to the computer but it wouldn't return from its sleep mode. I manually rebooted the laptop, XP loaded, I logged into my account, and after a couple of seconds, the screen went black again. I believe it was running fine, it's just that the screen seemed somehow disconnected from displaying what the computer was actually doing.

So I rebooted, logged into a backup profile I have in case my main profile gets messed up and I need to delete it and/or make new ones, and the backup profile worked fine. In fact, I'm using it right now.

I ran CC Cleaner and MalwareBytes just in case, rebooted, and logged into the affected profile - same problem. I could make a new account and copy over files/prefs, but I'd like to avoid going through that process if possible. Does anyone know how I can solve this issue?

Thanks for your time.

EDIT: I solved the problem, thanks to randomly pressing some keys after trying to log into the dysfunctional account again. After pressing fn+f2 a couple times the screen came back, albeit dimly. So I just pressed it a few more times until it was at normal brightness. So I guess the profile got set to have a completely turned-off screen, and all I had to do was undo that. Okay so feel free to delete this thread if you want. : )