can anyone tell me if this laptop is good enough to run the latest games on reasonably settings. 

HP Pavilion DV7T Core i7 /17.3''/6G RAM/750G HDD

-Intel Core i7-2630QM 2.0GHz (2.90GHz)
-Windows 7 32-bit Home Premium 
-ATI Radeon HD 6490M 1.0 GB GDDR5 SDRAM 
- Intel HD Graphic Family 
-HP HD Webcam with integrated digital microphone 
-17.3" HD LED
- 6G DDR3 RAM 
-USB 2.0x2 & 3.0x2 VGA (D-Sub), HDMI, LAN (RJ-45), Multimedia Card Slot 
-750GB Hard Drive Capacity
-Beats Audio with the HP Triple Bass Reflex Subwoofer 
-Blu-ray Player & SuperMulti DVD Burner
-Gigabit Ethernet LAN
- Standard Battery 

its second hand and asking price is $800 NZD which is 400 pounds and $630 USD

no it's not suitable for gaming. search for lenovo ideapad y580, it costs 670€. I think it's the cheapest notebook which you could consider as gaming notebook. but you need to stick to 1366x768. at that resolution you can play almost anything at max. for a 1920x1080 gaming notebook you need to spend 950+ €.

Can you elaborate. I thought that was a good i7 and the gpu seems ok. I dont want to spend more than $1000nzd and I dont want tot take anything less than a 17inch screen
but then again ive never onwed a laptop and am comparing the specs soley against the pc equivalent

I've got a 17.3'' HP that I really like. The screen is awesome, though it was hard to find a case for it. I don't game on it, however.

Still, unless you're all about the "graphics", you should be able to play most games on it at medium/low settings.

That graphics "card" is downright horrible and the GDDR5 is a useless marketing stunt for it.
A DDR3/GDDR3 Radeon 6530 or higher would wipe the floor with it, no contest.

With that machine you're essentially paying mostly for the Quad-Core Intel processor.
When it comes to a gaming laptop, the GPU comes first, you can't upgrade that hardware remember, then you take the CPU and Display into consideration. - With Ram and HDD don't consider them in your buying purchase, those are user replaceable.

I suggest as a starting point, look at an AMD APU in that price point, it will beat most of Intels offerings in gaming, something along the lines of the A8/A10 chips with a Radeon 7660G/7640G or 6620G/6520G.

http://www.tailormadecomputers.co.nz/shop/Tablets/Samsung/26279.html
this seems the best I could find. but it is not 17 inches, they cost 1150 ndz+.

http://pricespy.co.nz/product.php?p=2077257 that costs 1050ndz but there is no link to a shop. aswell no 17 inches.