Desktop freezes upon clicking icon or start menu

My computer is an HP pavilion dv7 1260us and I'm using windows vista 64 bit. Today my computer froze while running a complete scan using AVG free edition. I turned off the laptop using the power button and ever since then, my desktop keeps freezing up Ina way. Any time i click on an icon or the start menu after the desktop has loaded, the mouse icon turns into the busy symbol. The task manager won't open either after I press ctrl +alt + del. I have tried restarting my computer in safe mode and running the avg scan again but that either causes the computer to overheat and shut down or the computer freezes up halfway through the scan. I ran chkdsk once which took about 5 hours to complete and I am still having problems. The only thing I have downloaded/updated recently has been ccleaner which I did earlier in the day. Could having this program along with AVG be causing my computer to freeze up? I've had both these programs on my computer for about a year without any problems.

Sounds like a virus or other malware
If not that may actually be the hard drive
See if you can run these hard drive tests.


Hard drive scan usings SeaTools www.seagate.com/www/en-us/support/downloads/seatools

You could also check to see if the fan is running on your cpu and gpu and if the vents are dirty.