Monitor clicking on and off?

Hi, I bought My son a desktop for christmas and while playing W.O.W. the monitor clicks on and off during gameplay. I belive I need to update some componets. Here is a link to the specs of the computer

http://support.gateway.com/s/PC/R/1014827R/1014827Rnv.shtml

The monitor is a Mitsubishi Diamondpoint sb70 17" CTR. I have hooked it to another identical monitor and the same thing happens. Running MS Vista os.

I am going to install 2 gigs of ram. I will order from New Egg or Cruical. Any suguestions?

I also whant to install a graphics card. (no PCI slots are being used)
My concerns are:
What card will fit into the case?
Will there be a heat issue?
Will the power supply handle the card?
Can I keep the price under $200.00? Prefer under $150.00

I want to replace the cpu with
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116063
Will this work with the Gateway drivers? (plug and play?)

I hope I gave enough information.
Thanks for any help.

 

The first thing to do is install a PCI Express video card. You can get a great card for around $150.00 Just check NewEgg or TigerDirect. The CPU you linked to should run just fine, no driver or software changes will be necessary. The Gateway link provided doesn't mention the power supply. When adding a video card, the power supply is often overlooked and can be the difference between the new card working or not. So, get a good power supply of at least 450w with at least 20a on the 12v rail, if you can get one with dual 12v rails, do it; combined, the dual rails should be over 28a... according to the Gateway link, you already have 2gb of memory, and that is the max supported.

 

Thanks for the help.This is the card I am ordering.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121097
The computor has a 300w power suipply so I will need to update it. The actural computor specs are listed under the componet tab. I am sorry for that. Can you recomend one that is compatible with this configuation. New egg list 35 different ones and I am not shure wich to buy.

 

according to gateway, your Powersupply is only 300 Watts. Chances are you will need to upgrade it to be able to run a better video card. A quality power supply runs around $100-$150. Here's one that should work well for you. Its 610 Watt Power supply from pc power and cooling. I own that particular model and am very pleased with it. You can save $20 by ordering it direct from pc power.
A Nvida 8600 video card offers good performance and is reasonably priced, unlike the brand new ridiculously expensive 88's. and 8600 should last your son for quite some time. I'd get one with 512 megs of onboard memory.

Powersupply $120
CPU - $95
Video Card - $100-$150

Total - $340

Your power supply may work, if that is the case, you would only be spending around $220