Also could this be a contender?http://www.cclonline.com/product/74072/S12II-620/Power-Supplies/Seasonic-S12II-620W-ATX-Power-Supply/PSU0291/

Ok so that's better value than the other 2? Just checked the Radeon certified power supplies and XFX aren't one of them, but is that not a big deal?

Ok so mainboard is MSI 760gm-p21 fx
I have 2 x 2gb ram
Processor: AMD Athlon II x2 260 3.2GHz

current power supply is http://www.amazon.co.uk/500-WATT-ATX-POWER-SUPPLY/dp/7135799313/ref=sr_1_5?ie=UTF8&qid=1356726502&sr=8-5

As for budget I haven't really decided. depends If I get one for now thats good value and get another in the future or get one now that will last me for my next upgrade. However I have spotted a couple of reduced things online, are they good value?

http://www.amazon.co.uk/OCZ-OCZ600MXSP-UK-ModXStream-Power-Supply/dp/B001GLFD54/ref=sr_1_12?s=computers&ie=UTF8&qid=1356728747&sr=1-12

http://www.amazon.co.uk/Corsair-GS600-Gaming-Series-Bronze/dp/B008ODWQ5W/ref=sr_1_14?s=computers&ie=UTF8&qid=1356728907&sr=1-14

or theOCZ ModXStream ProPower supply- 500 Wattfor £46

I looked at the Corsair AX range and they seem to be a lot more expensive (not really within my budget).Any help much appreciated.

So I've got a Radeon HD 7770 recently, may consider getting another in the future, can anyone recommend a PSU that would be able to power both? or if this is really not worth doing a PSU that I'll be able to use now thats good value and/or one I'll be able to still use when I upgrade my card (if this is better than going crossfire). Thanks in advance for any help!

Ah ok, thanks for the help. I think my PSU is this onehttp://www.amazon.co.uk/500-WATT-ATX-POWER-SUPPLY/dp/7135799313/ref=sr_1_1?s=computers&ie=UTF8&qid=1356267716&sr=1-1 could this be the issue?

Ok so vista is totally up to date and it seems like everything is fine with the card... but loads of things still fail to work. And when I disable the card through my control panel, everything works fine again. But obviously my screen is still connected to my computer through the graphics card and is working fine... I am super confused. Could it be anything to do with my PSU? The card says it needs minimum 450w and my PSU is a 500w

just as a bit more info my windows system assessment tool stops working every time i try and run it and my catalyst control centre also stops working

haha of course. flip this is frustrating

yep I'm getting in to windows fine, have uninstalled then installed the drivers several times, ha e made sure the card is inserted properly, the computer seems to be acknowledging it is there perfectly well, i.e. if i look in my device manager it appears under display adapters, even saying that the device is working properly and the drivers are up to date... when I uninstall the drivers, windows sidebat, flash etc start working fine but then once i install the drivers again, then restart the computer i get the same priblems. any ideas?

thanks for the help but I have tried this quite a few times now and the same thung keeps happening. i can tell it hasnt worked ad soon as my computer is restarted as the sidebar never appears