not sure where to post this my son,s computer specs are as follows:
Asrock conroe 1333 D667 mobo
3.00GH dual core cpu
2 SATA HD 1 500G AND 1 80G BACKUP HD DRIVE
2G DDR2 memory
2 Dvd writers
I'm going to upgrade the graphics as it is an intergrated chip so was thinking Nvidia 8600 aslo hoping to add firewire card
However the PSU is only 400watts and im not sure it will handle everything so would a 500watt PSU be better. Also maybes 4G of ram instread of 2G

Hi jezzi. You have quite a good basic setup there, though strange the board is lacking firewire.

The addition of a graphics card will definitely be a boost to your system, though IMO the NVidia 8600 might not give the best value around. There's a few newer low-to-mid range graphics cards coming into view from both NVidia and ATI that might be worth taking a look at.

As for RAM, adding more is never a mistake!

most of the things in this computer i've put in myself but just wondering if the PSU thats in it will be enough to power it which graphics card would you suggest and what PSU would be advisable

"... wondering if the PSU thats in it will be enough ...
Sorry, amazingly I missed that part in my reply...!

I'd recommend stepping up to at LEAST a 500 Watt. Manufacturers? Well, I've never really had a preference on this - just ensure that the cables provide for your setup, then go for as low a noise level and as high efficiency as your budget allows.

I hesitate to make direct recommendations on these forums, but here's a service that could be useful to those looking into their power supply options. At time of writing, there is a free option that should fit most people's needs. Please note that this link is for your own research, and does not mean that the service is endorsed by PCTechGuide.

Power Supply Calculator

hi just to let you know have now replaced old psu of 400w with antec earthwatts 650 psu also replaced old case with new one so have more room for graphics, and tv card and a firewire card when money permits it

Great stuff jezzi - plenty of scope for upgrades there!