I've read other posts on isass.exe, but it's only my guess that this is causing the problem, and my circumstances vary slightly. isass.exe is in my task manager, and I'm told it's a trojan. I get pop-up windows all the time supposedly from the computer to me and I have this wierd little window thing that I found in the very top-left of my desktop. Here's a screenshot of it: http://i12.photobucket.com/albums/a224/doapics/k.jpg I can't find it in my manager or anything. Oh, my computer randomly shuts down, too. No 30 second warning, either. I've trying resetting the hardrive. I even went out and bought a NEW hardrive. I appreciate the help in advance!

What antivirus and firewall do you use? Most antivirus programs should easily detect and solve this problem. Go here for removal instructions and run Trend Micro's on-line virus scan called "housecall". http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=TROJ_ISAPASS.A

isass is a worm otherwise known as the sasser worm. lsass is part of windows. These are frequently confused. The icon in your screenshot at the top left hand corner looks like the recycle bin. Your picture isn't detailed enough to make out further details. Have you tried a right click and properties? Random shutdowns without warning are frequently caused by the power supply although an overheating CPU will also cause this.