At the start, my ThinkPad (A31) was dual booted via grub, Windows XP on /dev/hda1, sid on the rest, 2.6.15-homemade kernel. So I added a second hard drive in the UltraBay. I then copied the XP partition to the new drive -- dd if=/dev/hda1 of=/dev/hdb1 bs=$((1*1024*1024)). I double checked: XP booted and recognized both C: and D: drives. OK, I thought, and wiped Windows off the original drive, and took it all for Debian, with / mounted on hda1.
So, booting the original XP, it was able to see the new XP partition and read it. At this point I would have run CHKDSK to let it see if there were file system problems, but let's just assume it was OK.... At this point, BEFORE DESTROYING the working WinXP setup, you should have modified your /boot/grub/menu.lst to give you the option of booting the new WinXP partition. You needed to see if the new one worked before wiping the original. MS writes its OSes to only boot off of a C: drive. That means the WinXP partition has to be on the "first" drive. The machine I'm writing this email on has, at times, had WinXP on the second drive; to accomplish this trick you need to lie to the BIOS using the 'map' feature of GRUB. If you only have 2 IDE hard drives, you'd do it something like this:
map (hd0) (hd1) map (hd1) (hd0) This trick the BIOS (and WinXP) into thinking its on drive C:.You're probably in trouble, so I don't want you to get your hopes up. But, if you alter your 'menu.lst' to point to the new WinXP partition, and if you add some 'map' lines, and if the stars are aligned properly and hell has sufficiently frozen over, then you might get lucky here. Another thing is that WinXP sometimes keeps low-level system information at the END of its partition, and it looks like you dd'd only part of the partition. That doesn't bode well, but you won't know until you try.
Another choice would be to forget XP, except that it is on rare occasion (involving proprietary dial-up) handy. Yet another would be to bite the bullet, wipe the drive, repartition, reinstall that Other OS on hda, and then reinstall sid. Ugh, what a chore!
WAIT!!If 'dd' worked well enough, then maybe you didn't lose all of your data, even if WinXP won't boot. If you can't get it to boot from my advice above, or from help you get from others, then don't erase that partition unless you really had nothing you wanted to save! It's possible, assuming you have a WinXP CD, to try a non-destructive reinstall from the CD. There's probably even a "rescue" feature on the CD that might getting it working. If you can't get the WinXP system booting, you might at least save any files you want to keep by mounting the partition with Linux. If you have trouble doing that, you could reinstall XP to the old location (from your CD) and recover data first... then try moving it again.
It seems to me like you have more options that just "wiping" stuff! Dave W.