Windows is not very dual-boot friendly, mainly because it likes to screw with your MBR (Master Boot Record) without telling you which will give you a whole slew of problems to deal with.
Another thing, I tried out nTune and regret I even bothered. There's this "fine tune" and "coarse tune" automated tuning utility that is supposed to OC your hardware as much as possible without giving up system stability. So I decided to just do the "coarse tune" since it was 12AM and it was going to take 20min vs. the fine tune which takes 3 hours, left it running while I watched Life After People on the History channel. About 30min later I come back to see the comp has BSOD'd, yay. I restart it, I log in, it loads windows, I see my mouse and desktop, it freezes, then the screen artifacts like crazy. I'm not going to go into details on how I fixed it...all you need to know is that you should use Riva Tuner instead.
All is good now though, I believe I got my GPU clocking to 550MHZ vs. the stock 400MHZ; I haven't played with the memory speeds yet.
I'm thinking about writing a portable framework since I'm going to be working on Linux as well as Windows. Deving for both platforms shouldn't be too difficult since Linux is aware of the Windows partition and vice-versa so I can read and write to both when I'm in either.
The main issue with deving for both is DX and OGL, as you know DX doesn't work on Linux. I'm probably just going to have to add another layer of abstraction that makes the interaction with DX and OGL invisible. I need to think this through a bit more.