PC with big problems

Hey, all
As most of you know, My PC is as good as a piece of crap, now..
It has gone 4 days since I made a system restore on it, due it lagged pretty much. I restored it to Fabric settings, so it was like you never packed it up. Ofcourse I had to re-install everything after that, but that was no problems. Then, when I started up Napoleon: Total War, the monitor turned black, With no other option than turning of the PC manually. I tried again, and with same result. Thats never happend Ever before. So next was M&B, which is a much smaller game, and after about 10-15 min playing, the monitor turns black, just as in NTW. Today, it has happend 24 or 25 times, and its just Very annoying. I suspect the PC to be the real problem.
What ive tried to do without result: ReInstalling almost all drivers, Including Graphic drivers Several times, with different versions of drivers. Ive switched Monitor cables, (From a blue, pretty small one to a White bigger one). That didnt work either. I made a System Restore again, No result.
Besides, Mount & Musket wont install, says Error...
Im Very Very Very Grateful for any help

//Philip

Call me if you don't need it any more ill make a donation to a charity institute. Ill tell them that the owner has passed away .If you get what i mean Haiti donation

Try using your monitor with a diferent computer and see what happends if it turns black again then you can practise you musket skills on the monitor, if it does not you can do it with your graphic card