My Acer Wont let me log in

[chrisg547]

I restarted my computer and now it won't let me log in. It goes to the log in screen but it restarted the user picture and the background. I click the user and it says "Welcome" but then it immediately says "Signing Out". I've tried restarting it multiple times by holding down the power button because I can't turn it off by clicking the power off button. I have Windows 8 and my laptop is an Acer Aspire 7250-BZ600. Please help me.

 

[kapitalistas]

may help if you hiting F8 button when you press power button oN.