My kid's dell d600 with xp goes straight to stand by mode?

My kid's laptop d600 running xp goes straight to standby mode when it is turned on now. I can restart in safe mode and it will still run. I know it was low on RAM before this issue started. I tried several system restore points but it still will not load in regular setting and run. What can I do from Safe mode other than a system restore that may fix the issue? I don't know what she downloaded or played that caused this to happen. I know it was low on RAM and it was recently dropped.