This is my system
Computer Case - Galaxy Black Mid Tower Case with 450W PSU - £32.68 - http://www.ebuyer.com/product/136491
Mother board - ASRock M3A770DE - £50.80 - http://www.ebuyer.com/product/174597
CPU - AMD Athlon II X4 620 - £66.22 - http://www.ebuyer.com/product/173368
Graphics card - ATI HD 5750 1GB GDDR5 Dual DVI - £104.18 - http://www.ebuyer.com/product/177117
RAM - CORSAIR 4GB DDR3 - £80.00 - http://www.ebuyer.com/product/178943
FAN - Cooler Master Hyper 212 - £18.50 - http://www.play.com/...earchtype=genre
Hard disk - Seagate OEM 500GB Barracuda - £39.94 - http://www.ebuyer.com/product/158860
OS - Microsoft Windows 7 Home Premium - £75.05 - http://www.ebuyer.com/product/173791
(If the 450w is not engough)
PSU - ANTEC PSU BASIQ 500W A/PFC RET - £46.90 - http://www.ebuyer.com/product/114929
DVD drive - Sony AD-5240S 24x DVD±RW - £15.80 - http://www.ebuyer.com/product/170014