Laptop errors, programs freezing, runtime errors

Have a Toshiba Satellite from 2010.
Programs are freezing and am getting white, blank screens on the programs.
The computer freezes and can't do anything.

Wanna find a way to stop this erratic behavior.

Downloaded SpeedItUp Free to optimize hard drive and defrag, but it never makes it through the 3 hrs. of scanning before getting runtime errors, and the program shuts down.

Kept getting this message:
"Logon process has failed to create the security options dialogue. Failure- security options."

Also these messages:
A problem has been detected and windows has been shut down...

IRQL_not_Less_or_Equal

This application has requested the runtime to terminate it in an unusual way.

Am running AVG Antivirus now, ran it earlier, to see what's wrong.

Any ideas would be appreciated.

System info to follow.