Okay this explanation is a bit longer ... but I start at the beginning: I've been using Windows 7 for a very long time, shortly after the release of v12.10 I installed Ubuntu via Windows installer. Everything worked fine but the fan of the graphics card.
After a bit of research I found out, that I just had to select a different driver (nvidia-current (proprietary, tested) worked pretty well). This also fixed some graphical bugs when I just logged into my account.
Due to my university I got a MSDNAA-Account (allows me to download every Windows OS for free). I downloaded and installed Windows 8. After configuration I installed ubuntu via the Windows installer once again and the first couple launches of ubuntu went well. Suddenly ubuntu didn't launched anymore...caused by some hard-disk errors and had no clue what to do. So I kept working on Windows 8 - unfortunately.
After playing around with the new Windows, I put my PC to sleep-mode. I couldn't wake my PC up and it wasn't responding to anything (neither mouse-movement, -clicks or keyboard strokes, nor the power-button and the reset-button worked), so I pulled the plug. Turns out, this was a huge mistake. Somehow the BIOS broke and after restarting a couple of times, the BIOS repaired itself. Neither Windows 8, nor ubuntu where bootable.
Now I had to install ubuntu several times, because after rebooting unity was hidden and I didn't know what the problem was and how to fix it. I finally realized that this problem was caused by the graphics card driver, which I've changed to the nvidia-current (This dirver worked fine before my PC "crashed").
So I installed Windows 8 again and after a bit of usage I installed ubuntu once again (via DVD). The booting of ubuntu and windows works fine - so far. But I'm still not able to change the graphics card driver without unity hiding away after restarting the OS. The noisy fan is really disturbing my work...
Processor: Intel Core 2 Duo COU E8400 @ 3GHz x2
Memory: 7.8 GB
OS type: 64-bit
Graphics Card: GeForce 9600 GT
Motherboard: Asus P5Q
I hope the information given are enough.