Graphic card not in function until well after startup

[FONT=Verdana, arial, sans-serif]So I've recently updated my custom build computer to Windows 8, and everything worked wonderfully, except for audio and GPU (GTX 480) usage. Sound worked, but it was ridiculously crackly, both in the front and through the monitor port (HDMI) to the point where I just turned it off. This was fairly late at night, and I had repeatedly tried to fix it, to no avail. So I decided to play Minecraft. I boot it up, and the first thing I notice is the drop in FPS. Whereas I normally got around 200, I was getting 50-60. I'll figure this out tomorrow, I thought. Now here's the weird part: all of a sudden, it all started working. There was a next to immediate increase in FPS, and when I turned on sound it was working wonderfully.[/FONT]
[FONT=Verdana, arial, sans-serif]Fast forward to the next morning, When I boot up Windows I have the same problem, again, and after about an hour it goes back to normal.[/FONT]
Thank you in advance.

Bump.

Welcome to EightForums, maurituna.

Sounds like a loose hardware connection somewhere. (No pun intended)

I highly doubt that's it, since it works fine under Ubuntu. I'll go check.
Also, thank you for your welcome, and sorry my first post was asking for help; I'll do my best to help around here .
EDIT: Nope, n luck, tightened, and even tried moving the GPU to another socket. Next step might be downgrade to Windows 7. Sucks.

I'd say not to give up yet. I'm not that savvy, but I just read a thread the other day about a driver causing spikes in something. I think they got it resolved. I'm on my phone. Do a search on "spike" or "spiking " to see if you can find it.