Need help since games such as Left 4 Dead 2 aren't working properly.

Its a problem with my graphics card I believe?

NVIDIA GeForce 9100, a part of the motherboard. What graphics card would I need for games such as this to run smoothly in High graphics settings?
Also this would have to be in sync with my power supply of 300 watts or if I have to upgrade my power supply, I'd need help with this too

get a 260 if you like nvidia, its a nice card imo.

Moar Opinions? Also do I need an upgraded power supply?

well, you probably have to upgrade your psu

three hundred watts isn't that much

what's the total specs on that rig?

HP
AMD Athlon II X4 620 Processor ~ 2.6GHz
6 GB Ram
640 Gb Hard Drive
Windows 7 64-Bit

What error do you get? I helped fix someone who had this problem earlier today.

No errors just a really bad lag the whole time. I turned down all the settings to minimum and played single player. Lagged a little but it was alright. I wanna be able to play in HD widescreen since my monitor is huge.

Bump.

Lol you post this is a section where nobody knows jack about computers (which is unfortunate).

The reason you can't play L4D(2) is because the GeForce 9100 is an onboard graphic solution (a shitty one at that).

The rest of your computer is okay, the AMD Propus being a very good low-budget processor.

Your answer will be below this line, however I'm curious, why/how do you have 6gb of ram on a dual channel motherboard? You should stick to multiples of 2^x (2gb/4gb/8gb).

Anyway;

To answer your question, you're looking at about ~150$ to upgrade your computer.

1) new power supply
2) new video card

Power supply I suggest anywhere from 500w+

SIDE NOTE: If you want a very nice video card/power supply at a very good price (atm) ~200$

Get this: http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.329244

Very nice video card, top tier brand and it supports DX11/Eyefinity.

Power supply: (Brands: OCZ, Corsair, Antec); (450w-600w)
Video card: Depends on budget

~~ $100 total
ATI HD4670
~~$150 total
ATI HD4850/HD4870/HD5750
~~$200 total
The combo I linked you.

This is assuming you live in USA, if not then ignore all the prices.

If you need help, lmk.

This post was edited by PENandPAPER on Feb 10 2010 01:21am

This, good advice. Pretty much exactly what I'd suggest, if your budget won't stretch that far then try:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814143160 9800GT @ $89
+
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182199 530w 80PLUS Cert @ $59
=$150 total and will run everything very well.