I would like to upgrade to 7.10. I have a dual boot machine, XP and Ubuntu. If I do the upgrade from the Update Manager will my XP still be there? Will any of my XP files be overwritten? I have Ubuntu on a separate hard drive. I do not think I upgraded before but my grub OS selection screen has both Ubuntu kernel 2.6.20-15 and Ubuntu kernel 2.6.20-16 besides XP.

I think you are making things too complicated for yourself...

1st thing, your boot-up screen will show 2 kernels if at one point you did a regular update, Ubuntu looks for kernel updates and installs them as soon as you tell it to. Therefore, you will have 2 kernels, and you will automatically boot into the most recent. (regular update opposed to system update)

2nd, if Ubuntu is on a different drive, your Windows files will not even be touched. The only thing they share in common is that GRUB (installed on your Primary Master) is recognizing the Windows drive. (in actuality, grub isnt actually reading it as Windows, it is simply how you set up your menu.lst file, you could name it "crappy os" for all it matters)