I recently got a new graphics card (GTX 480) for my 2 and a half year old system. I installed Windows 7 64bit (previously I had XP 32 bit) and added some more RAM. After installing the OS, the system ran excrutiating slow, taking at least 30 seconds to open a window. It also sporadically failed to boot, showing a grey gradient.
I tried reinstalling the old graphics card (7950GT) and it still doesn't work, it now gets as far as a black screen with a mouse cursor.
These are my specs:
Asus P5n32-SLI SE deluxe motherboard
Asus 7950GT - replaced with Inno3D GTX 480
Core 2 Duo 6600
4 Gigs RAM (previously 2)
Hiper 530W PSU
Samsung SP2504C hard drive
What's going on here? Was this caused by the OS, going 64 bit, or did I overload the PSU with the new card?
I realise this is quite vague, but any help/advice would be appreciated.
I don't mind replacing the mobo/ram - I got this computer when I was still a student and on a limited budget; I've got a bit more money to throw around now. That said, I might get a psu first and see how it goes - is 850w overkill?