It depends on what you changed in msconfig.

If you just want the message gone put msconfig back how it was it should be fine after.

Don't expect more than 10.

But the rest of your comp will run noticibaly faster.

Sounds to me like you have serious Malware issues. If you already have Avast uninstall and try AVG Free see if it picks up anything that Avast missed. If AVG cant find anything next time it happens check the task manager to see what process is draining your resources. If the process name is unfamiliar google it and see what shows up (dont worry if its svchost.exe its a windows process usually there are some virus versions). If you still have issues after that you the next step is reinstalling XP. If after that nothing changes you might have to reformat your drive.

I also dont think that its hardware related.

Good luck.

iDump is the one I use.

http://www.download.com/iDump/3000-2169_4-10407429.html

Free and everything

Don't take the case off.

Post your mobo model and what case you have it in.

Depends on what you mean by run Medium settings at 1200x1080 yes most anything. If you mean max out at a higher resolution then the processor is a little slow and maybe a 8800 would suit your needs better more ram couldnt hurt either of course. Now if you want to max Crysis you will need some serious upgrades.

Crysis is fun for a while but you need a beast to run it.

Halo and Halo 2

Well in general the more you spend the more you can do. But I'd suggest you get a desktop half the price double the performace.

If its got to be a laptop stick with the big brands Alienware is gonna be the best but it will cost ya. If you dont want to spend the $2500 for one of those Dell XPS.