This has just begun recently and on two computer games so far. At random times my computer screen goes black. Everything in the PC tower goes silent, no fans, no sounds fx from game, no nothing, but the blue light of my PC stays on.
I've tried to Alt+Tab and Crtl+alt+delete to get some sort of responce but nothing.
Windows: Vista 32-bit
Processor: duel Intel Core CPU email@example.comGHz
Graphics Card: NVIDIA GeForce GTS 250
If I had to guess it is your PSU. They degrade over time and yours could be at the point were occasionally during gaming the system needs more power than the PSU can deliver. Gaming stresses both the GPU and CPU causing more power to be drawn. When the PSU can't keep up the system shuts down.
What PSU do you have exactly and how old is it?
Ah, yeah. That thing has no business running a GTS 250. Usually you will want at least a 400w PSU for that card. When did you install it?
I'm surprised the system started up at all with it installed but you were pushing the PSU to its limit which will drastically shorten its lifespan. You will need to replace it. This would be a good choice; http://www.newegg.com/Product/Product.aspx?Item=N82E168...
It's very high quality and a good deal.
BTW, your processor is quite weak for current games and is keeping that card from its full potential. If you tell us what motherboard you have you may be able to get a much better CPU fairly cheaply. If you don't know what board it is run this; http://www.cpuid.com/softwares/cpu-z.html
and click on the mainboard tab.
Tell me what board you have.
Also I spotted this if you prefer; http://www.newegg.com/Special/ShellShocker.aspx?cm_sp=S...
Really the other would be more than good enough but that is a very nice deal if you would like something more powerful. The "shell shocker" deals only last one day so if you want that you would need to order it tonight. The combo with the case is also a very good deal if you are interested in such.
Alright, unfortunately your motherboard only supports Conroe based core 2 duos. The one that would be the best upgrade would be the E6700 at 2.66ghz. If you want one make sure the one you get is the right processor. Intel has another chip called the E6700 which is much newer, runs at 3.2ghz and is based on the wolfdale core.
Your ram is DDR2 as is the motherboard in that combo so you wont need new ram.
I recommended the older E6700 because it is a Conroe C2D which is what is compatible with your current motherboard according to the HP site. You will likely need to find it used. The newer E6700 is certainly faster but it is a Wolfdale chip that you can't use without replacing the motherboard.
The combo I linked is cheap and good but if you would prefer a better processor I noticed that the Corsair PSU I linked above has a combo with a Phenom II x2; http://www.newegg.com/Product/ComboDealDetails.aspx?Ite...
Those processors actually have 4 cores but 2 of them are locked by AMD. However there are motherboards that can unlock those cores. Occasionally a core will be locked due to a manufacturing defect but most of the time they are actually fine. So with that processor it is very likely you will end up with a Phenom II x4 at a much lower price then it would otherwise cost. Even if both cores don't work you will have a x3 which is still quite nice. Here is a reasonably priced motherboard that can unlock the cores if you want to go that way; http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I believe in total it will be $40 more than the other combo. It is what I would recommend but then it's not my money. The Athlon II x2 will be decent for current games if $40 more is too pricey.