I've tried to achieve that in the past and failed, I couldn't get my installed Windows XP to boot from a real partition, I could install it using QEMU and use it fine.

Gaming? Slow pal.. no 3d acceleration, generic drivers and it's emulated.. not good.

I remember seeing a thread about this some weeks ago, a search may help you.

Edit: This is the thread I was talking about: http://www.linuxquestions.org/questi...d.php?t=465123

Yes, it is possible to boot an operating system from a physical partition inside of Qemu, but it isn't recommended. If you insist, this is the method:

qemu -snapshot -hda /dev/hdb3

replace "hdb3" with the partition you want. "-snapshot" prevents it from making changes to the partition. Games load SLOWLY. I've tried it before and have seen load times of 15 minutes where in Windows natively it is less than a minute. In all honesty, I'd recommend looking into getting a copy of VMWare if you wanted to play games... or dual boot.

Back when I started using Qemu, the documents said it wasn't recommended. Now all mention of how to do this seems to have been removed. If there is a miscalculation in the program or you type /dev/hda instead of /dev/hda1 it could be possible to overwrite other data than that which you had intendid. I'm sure there are other reasons, but those are the two I can think of off the top of my head.

I should probably note that I've always just created an Qemu image and installed the OS into it.