Your video card is rated 30.8 FRAPS which will play most games at full settings but will probably not play the most extreme games at full settings.
FRAPS: refer to:
http://www23.tomshardware.com/graphics.html
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My opinion for a new video card:
For playing the latest most extreme games a FRAPS (frames per second) of 50 or higher
For moderate games a FRAPS of 30 or more.
For no games a FRAPS of 18 or more
Refer to:
http://www23.tomshardware.com/graphics.html
Ratings are for a PCI x16 card installed on a computer similar to the test machine.
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Other options
XFX PVT73AUDF3 GeForce 7600GT 256MB 128-bit GDDR3 AGP 4X/8X Video Card - $109.99
FRAPS = 40.9 (rated 5 stars)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150233
XFX PVT71KUDF3 GeForce 7900GS 256MB 256-bit GDDR3 AGP 4X/8X Video Card - Retail- $149.99
FRAPS = 52.2 (only rated 4 stars)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150174
XFX PVT71AYDF3 GeForce 7950GT 512MB 256-bit GDDR3 AGP 4X/8X Video Card - $214.99
FRAPS = 71.8 (only rated 4 stars)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150223
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Higher performance cards require more current from the 12 volt leg of the power supply that supplies the video card. This may require changing to a more powerful power supply. Determine the amps at 12 Volts the video card recommends and compare it to your existing power supply.
If you need to buy both a power supply and the video card which could run $150 to $300, I would be tempted to bite the bullet and just build a new computer.
How to Buy a Power Supply
http://www.wikihow.com/Buy-a-Power-Supply
Nvidia SLI Certified Power Supplies
http://www.slizone.com/object/slizone_build_psu.html
ATI Radeon Crossfire Certified Power Supplies
http://ati.amd.com/technology/crossfire/buildyourown2.html
Diamond Video Cards Certified Power Supplies
http://www.diamondmm.com/certified.php