The first thing I'd check would be your temperatures. I use SpeedFan which you can download for free, but there are others as well. You want your temps under 50 degrees C. You could boot to Safe Mode and check for viruses and malware. You could also look at the very cryptic system event log for entries flagged "error". As you might guess, there're lots of possibilities, but the above 3 things are good for starters.
My computer has been freezing up every time I log in. Sometimes it might be during the blue welcome screen or it might be when I open firefox. I've had my brother check for anything and he said that there wasn't anything wrong when he opened up the computer. My guess is that it might be AVG but I'm not too sure. Any help will be greatly appreciated.
I'm not 100% sure of my specs so I couldn't tell you.