The cheapest (as basic as you really want to go) new system you will find for playing music and browsing the internet
Crucial 1GB (2x512MB) DDR2 PC2-4200C4 Dual Channel Kit (CT2KIT6464AA53E)
(£16.44)
Samsung SH-S203D/BEBN 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM
(£16.44)
Gigabyte GA-73PVM-S2H GeForce 7100 Micro-ATX (Socket 775) PCI-Express DDR2 Motherboard
(£49.34)
Antec NSK 4480 Mini Tower Case (Silver) - 380W Earth Watts PSU
(£52.86)
Intel Celeron E1200 1.6Ghz Dual-Core Processor (LGA775) - Retail
(£30.54)
Hitachi Deskstar T7K500 250GB SATA-II 8MB Cache - OEM (0A33423)
(£32.89)
Total : £211.37 inc VAT and Delivery
Basic system - enough of everything to run basic games, watch films and listen to music, large storage
GeIL 2GB (2x1GB) PC2-6400C4 800MHz Ultra Low Latency DDR2 Dual Channel Kit (GX22GB6400UDC)
(£29.36)
Samsung SH-S203D/BEBN 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM
(£16.44)
Sapphire ATI Radeon HD 3450 Silence 256MB DDR2 TV-Out/DVI/HDMI (PCI-Express) - Retail (11125-00200R)
(£25.84)
Antec NSK 4480 Mini Tower Case (Silver) - 380W Earth Watts PSU
(£52.86)
Intel Celeron E1200 1.6Ghz Dual-Core Processor (LGA775) - Retail
(£30.54)
Gigabyte GA-P31-DS3L Intel P31 (Socket 775) PCI-Express DDR2 Motherboard
(£46.99)
Samsung SpinPoint F1 500GB SATA-II 16MB Cache - OEM (HD502IJ)
(£46.99)
Total : £261.88 inc VAT and Delivery
Much better system for everything at the loss of HDD space, can be upgraded in the future easily enough though and 160gb will see her through a year or two
Western Digital Caviar Special Edition 160GB SATA-II 8MB Cache - OEM (WD1600AAJS)
(£30.54)
Intel Core 2 Duo E2180 "LGA775 Conroe" 2.00GHz (800FSB) - Retail
(£45.81)
GeIL 2GB (2x1GB) PC2-6400C4 800MHz Ultra Low Latency DDR2 Dual Channel Kit
(£29.36)
Samsung SH-S203D/BEBN 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM
(£16.44)
Gigabyte GA-P31-DS3L Intel P31 (Socket 775) PCI-Express DDR2 Motherboard
(£46.99)
Gigabyte SUPERB 460w PSU
(£25.84)
HIS ATI Radeon HD 3650 512MB DDR2 TV-Out/Dual DVI/HDMI (PCI-Express) - Retail
(£48.16)
Antec Three Hundred Ultimate Gaming Case
(£35.24)
Total: £290 inc VAT and Delivery
Best rig for the money - Can play new games, watch films easily and do anything you want it too
Intel Core 2 Duo E2180 "LGA775 Conroe" 2.00GHz (800FSB) - Retail
(£45.81)
GeIL 2GB (2x1GB) PC2-6400C4 800MHz Ultra Low Latency DDR2 Dual Channel Kit
(£29.36)
HIS ATI Radeon HD 3850 Pro 256MB GDDR3 TV-Out/Dual DVI/HDMI (PCI-Express) - Retail
(£76.36)
Samsung SH-S203D/BEBN 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM
(£16.44)
Gigabyte SUPERB 460w PSU G
(£25.84)
Abit IP35-E (Socket 775) PCI-Express DDR2 Motherboard
(£58.74)
Seagate Barracuda 7200.11 500GB SATA-II 32MB Cache - OEM (ST3500320AS)
(£55.21)
Antec Three Hundred Ultimate Gaming Case
(£35.24)
Total : £355.87 inc VAT & Delivery
dont bother with the cheaper ram as ddr2 800 is only a pound or so more, the only things you need to decide is what gpu to use and how much storage is needed.