Im looking to buy an affordable gaming computer that would run games like call of duty, dead island, oblivion ( the newer released games). My budget is around £400.
Well I wouldn't regard a system with on board graphics as a great gaming PC.
The general rule has always been to use a high spec card on top of a good quality processor and Mobo.
For this money, I can only assume a lot of the components are budget. The box will probably not be upgradeable .. or have any spare slots.
The pc's description is a bit scarce, with no indication of power supply size, motherboard details, ram memory poorly described (in the title as DDR3 but not in the description).
Onboard graphics is not really good enough for gaming. You need a decent graphics card and most of them would need a quality psu. The case is an older Coolermaster design.
As AlBags says buy from a reputable computer supplier and I would recommend Overclockers as well, get most of my bits from them.
The problem here is that game specs are increasing all the time. Even if you get a reasonable bargain, it is likely that in a few months a new game you want won't run.
I am helping my nephew build a pc at the moment and we have already upgraded twice in the 3 months since we started because a game he wanted to get wouldn't run on the initial spec.