This would be a good option for $ 135 (but there is a problem *)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814500270&cm_re=GTX_660-_-14-500-270-_-Product
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That's your Computer, right ???
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c03933829&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=5399024
* The problem is it has a 300 watt PSU only. The A8-4500 needs 65 Watt and the GTX 660 140 Watts.
However in a build you will come close to the 300 watt usage. See here: http://pcpartpicker.com/p/8vQbcf(See: Estimated Wattage: 294 Watt)
This will never work in real life. !!! (That cheap 300 watt PSU's would never draw 300 Watt continuous power)
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So, you forget your max skyrim settings, and either you buy another PSU (Power Supply) or choose another GPU (Graphics card)
This one should work fine. It doesn't need an extra 6-pin PCI-E cable from your PSU.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814500349&cm_re=GTX_750Ti-_-14-500-349-_-Product
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I need some specs from your PSU too: http://oi60.tinypic.com/2pzgs3k.jpg