Q6600 4gb memory. (Vista is 32 bit so it only detects 3gb) 500gb harddrive 256mb nvidia geforce 8600gt-ddr3 So my computer started freezing out of nowhere. The entire screen would get greyed out and sometimes turn black. It will be running completely fine and it will just stop. And when it stops it doesn't even seem like it's being overwhelmed by anything. I ran my antivirus/anti spy/anti adware and found nothing. I suddenly have an extra 50 gb on the harddrive, but can't find anything that's missing. I thought all my music and porn got deleted at first. And occasionally I get this error... "Logon process has failed to create the security options dialog. Failure - Security Options" And sometimes when I try to do something, it will say I need to be an administrator. But I am one.