CPU
BX80562Q6600 SLACR - GO - Intel Core 2 Quad Q6600, Kentsfield Core, S775, 2.40 GHz 1066MHz 8MB Cache, 9x Multiplier, Retail - Scan.co.uk
£145
MOBO
ASUS P5K PREMIUM/WIFI-AP ATX LGA775 QUAD CORE P35 1333FSB 8GB DDR2 SATAII 6 PORT RAID CROSSFIRE GIGABIT LAN WIRELESS AUDIO :: Pentium® 4/Celeron (Socket 775) :: PC Motherboards :: Click-A-PC - custom computers, custom built pc, computer components
£120
GPU
XAE/48500+T352-PM9048 - 512MB Palit HD 4850, PCI-E 2.0(x16), 1986MHz GDDR3, GPU 625MHz, 800 Cores, 2x DL DVI-I/ HDTV, HDCP - Scan.co.uk
£119
RAM
TWIN2X2048-8500C5D - 2GB (2x1GB) Corsair TwinX DDR2 XMS2 Dominator, PC2-8500 (1066), 240 Pin, Non-ECC Unbuffered, CAS 5 - Scan.co.uk
£34
HDD
250GB Hitachi HDP725025GLA380 Deskstar 7K500, SATA 300, 7200 rpm, 8MB Cache, 8.5 ms, NCQ - Scan.co.uk
£32
OS
Computer hardware and software at amazing prices, available online - Scan.co.uk)
£85
Case
THREE-HUNDRED EU - Antec Three Hundred Black Midi Tower Case w/o PSU - Scan.co.uk
£42
PSU
530W Hiper HPU-4M530 V2 SLi Ready Black ATX2.2/BTX SATAx2 PCI-Ex2 - Scan.co.uk
£41
£618
you then just need to source a monitor and speakers keyboard and mouse :)