New GPU OS won't boot.

[CuriousAmateur]

All right so I finally sorted this out with a visit to a local Tigerdirect. Advice to anyone with a failing GPU/computer setup, do not be wary of spending however much you can to reach your goal. Also, if you're NOT a pro hardcore engineer (welcome to my world) please make sure you get someone very tech savvy to look at it. I was lucky that I got an extremely dedicated worker at the store to help me.

For those with Dell XPS 8300's, forget all the rumours about Dell having a great PSU that's underrated. It's actually overrated. A good tip to remember that if the PSU is silver, it's overrated, black is always the better one.
It was to no wonder that my PSU couldn't handle the GTX 560; it was probably only 300W instead of the 460W it was advertised as.

So all in all, I had to buy a new 600W CoolerMaster PSU, one 120 mm fan (control air flow) and settle for a lesser GPU (BiOS kept crashing with the GTX 560; Damn Dell motherboards aren't compatible apparently.)
But I got an EVGA GTX 550Ti with 2 gigs of memory which after some benchmark tests, turned out to be as good as the 560.

So I'm happy! Thanks for the help guys.

 

[Termie]

Glad you figured it all out. If the video card didn't work with the new psu, I can pretty much guarantee it was the motherboard all along - it was what was causing the 560 to crash. So you probably didn't need the psu. But that's Ok. Investment for the long haul.

As for the 550ti, it's not a great value (the hd7770 I mentioned before is much better), but what matters here is you got it working to your satisfaction.

Enjoy!