win7 dual boot: replace win2k with xp?

I have a dual boot win2k and win7 (win2k installed first and win7 installed in next partition)
I want to install xp over the win2k partition and keep the win7. My guess is that may cause win7 disappear from the boot menu or both os are not bootable.

Does anyone did such thing successfully? Any advises?

Thanks

Please don't double post!

Normally, you should be able to choose which partition to install on during the install.

Though, it might be a good idea to make a backup of Windows 7 with softwares like Acronis or Macrium.