With a laptop, the fan issue is not as easy to replace as a desktop machine. Try and run it in a room of your house that is cooler than where it is now. There is a program called "mothermoard monitor" that will read temperatures of MOST processors inside computers. That being said, it is an older program that takes some tricks to get working. A basic search will get you plenty of information on it.
As for getting back a piece of software via System Restore. Here's how it works. Just think of everyday of the week -- if on Monday you install IE7, which takes the place of IE6 -- and you do a system restore to Sunday, the night before Monday -- it will reset your system to when you had IE6 installed. It will not revert you to nothing.
Imagine the computer taking a snapshot at random intervals of all the programs installed at that current time. System Restore is great for when you believe you have having software problems from a recent install or uninstall and need to GO BACKWARDS to revert to a state that was more stable.
With you having a laptop, does the same issue arrise when only using the trackpad? (aka, no mouse attached). How much system memory do you have? (Right click my computer, go down to properties, wait a moment, and it will show the specs. of the system along with processor speed and memory, etc.) Does this happen when you are plugged into the wall via AC power? Does it ONLY happen when IE is opened? Do you have issues when using Firefox? Other programs? Try and figure out a way to isolate the problem and find out which programs trigger the response. If you get the same response (freeze) from different programs, it would lead to a computer/hardware problem. Isolating a piece of software as the trigger, obviously makes it a software issue.
I'll be back later tonight. Good luck.