Problems with my new video card. Please help?

Hey guys well ive been having some problems recently with a new video card i bought (well i think this is the problem because i didn't have this before buying this card) Well after installing my new video card and updating my drivers i started up company of heroes and it was all going smooth until i got "Monitor going to sleep and No input signal" i couldn't do anything but reboot my system manually after trying to plug in all the cables correctly.I decided to try another game this time Black and white 2, It was all going fine until the game froze and it took me back to the desktop saying "VPU Recover: your graphics...." . One thing i noticed and i think may be the problem is maybe my power supply is not enough for the new video card because it says on the box that the graphics card needs at least 450 watts and i only have 300w is that the problem?. I am really desperate to find a solution to this problem my specs are:



HP Pavilion a1600n

AMD Athlon 64 X2 DUal core

Ati Radeon HD 4850<<<<< THIS IS THE NEW GRAPHICS CARD

1024 MB

200GB of HD

my Power supply gives 300 W



Additional: If the Power supply is the problem what would you recomend for me to get.|||You are absolutely under supplied. If you are going to do any PC gaming with today's games you should have AT LEAST a 600W power supply. This will ensure that your card runs properly and also that it will not overheat and burn out ....bye by graphics card. It will also allow you to upgrade cards later. I would also look at bumping up the RAM to 3 or 4 gigs as 1 is just not enough these days. Hope this helps|||Power is too low. If you can, get this.



http://www.newegg.com/Product/Product.aspx?Item=N82E16817182030