Sorry I didn't get back to you last night.
1] Did you check the inside of your computer for any overbuilding of dust inside your machine as DBCooper suggested? If there is a build up, this can cause a system to shut down due to overheating when under stress (like gaming)
2] Did you manage to download and run the file that spunk.funk asked you for as it's a great program and way to figure out what the issue is.http://sysnative.com/0x8/BSOD_Windows7_Vista_v2.64_jcgriff2_.exe
3] Did you manage to back up your documents yet?
Right, just been looking over your autoruns file and it doesn't look too bad. You have a few browser toolbars that you don't need (unless you want to keep them) as they are just another thing that your browser has to load every time it starts. You probably got them whilst installing another program and missed the check box during the install.
To remove these go Start>Control Panel>Add/ Remove Programs, and you will see the toolbars in there.
Windows Live Toolbar
Again, it's upto you if you wish to keep them ot not.
I would also uninstall Norton using the Norton Removal Tool
and replace it with Microsoft Security Essentials
instead. Download MSE first, but don't install it until Norton has been removed and you have rebooted. Again, using MSE instead of Norton is my preferred choice as Norton causes quite a few issues at times. You can always re-install it later if you wish. (If you do, make sure that you have uninstalled MSE as running more than one anti-virus will cause system conflicts)
In the Error log that you supplied, there are a lot of SideBySide Errors with different Event ID's. You should be able to resolve this by installing the latest .NET Framework which is currently version 4. You can get this in 2 ways.
1] Start>All Programs and select Windows Update. You should see it available there. Try this option first.
2] You can download it here
. It may require you to uninstall previous .Net Framework updates first via add/remove programs (Start>Control Panel>Add/ Remove Programs (at the top of the window, check the 'Show Updates' box)
Can you make sure that you computer is also fully up to date via Windows Update.
I am also re-attaching your Error Logs in .pdf format and data sorted (easier to look at and couldn't attach as xls) so that other people can look at them and help out if they spot anything. The only ones you have to worry about are the ones that show up in red in your Events Logs. Some of these may be resolved by making sure that your system is fully up to date.