New computer

[Coontang]

With a new phone contract due soon, I will be raking in a lovely cashback amount and I am thinking of investing into a computer. My idea to buy a new computer comes from the frustration of downloading or buying games and being disappointed at having to dramatically reduce settings to achieve a playable standard of framerate. Heck, I have to run Trackmania on fairly low settings at the moment, and effects such as motion blur and bloom can be forgotten about completely!

Current software:

AMD Athlon 3400 (2Ghz)
1.5GB DDR Ram (333Mhz I believe)
GeForce 512mb 6600
Shitty HDD

My current choice of hardware is this:

Arctic Power 700W PSU - 4x SATA 1x PCI-Express
2 x Corsair 2GB DDR3 1333MHz Memory Module Unbuffered (4GB total)
Casecom KM-9188 Black Mid Tower Case with Full Black Interior/Exterior 120mm Blue LED Front Fan
Gigabyte GA-G41MT-S2P G41 Socket 775 DDR3 Onboard VGA 7.1 Channel Audio mATX
Intel Pentium Dual Core E6600 Socket 775 3.06GHz 1066FSB 2MB Cache Retail Boxed Processor
Palit GTS 450 1024MB GDDR5 DVI VGA HDMI Out PCI-E Graphics Card
Western Digital WD20EARS 2TB Hard Drive SATAII 64MB Cache - OEM Caviar Green

I'm thinking this should give me a decent mid-range PC which is a huge step up from my current system and the whole lot costs around £350. Do you think this is worthwhile, and will I have any problems putting this system together? I'm hoping this would allow me to play some games such as the Call of Duty series, Half life 2 series games and possibly others such as Witcher 2 at a reasonable standard of graphics at a maximum of 1680x1050.

Also, the price range isn't fixed. I would be happy to splash out a little more on certain items if it guarentees me a reasonable increase in performance.

I'm also thinking upgrading in steps (ie. buying the Hard drive, then the system without the graphics card and then a graphics card at a later date), but I am worried about compatability issues with my current hardware and such.

Do you think it would be a good idea to try and build such a system, assuming I can find the correct tutorials and such online?

Any other recommendations for my gear would be much appreciated!

Cheers

[ultralala]

The CPU is may too slow for a 450 GTS. I recommend a e8400 or better Q9550

[daniel]

I would like to point out you selected a micro motherboard and a mid size computer tower. This can be good if you want the extra room. However a micro sized computer tower has the advantages of taking up less space.

[Coontang]

I would like to point out you selected a micro motherboard and a mid size computer tower. This can be good if you want the extra room. However a micro sized computer tower has the advantages of taking up less space.

Thanks for pointing it out to me. Yeah I noticed I'd picked a micro motherboard - my current computer is a micro motherboard in a mid size tower. I would upgrade to a full size motherboard but I feel the money could be better spent and I don't think it would really be an issue using the micro. Also, room space is not an issue