you can delete the partitions, and create new ones, or just format those in fat or ntfs so windows will see them. as for xp still booting,
http://www.linuxquestions.org/questi...003/08/4/86345
that link pretty much answers the questions without me having to type it.
if windows does not boot, just use the cd to repair. dont format, just repair/reinstall, and you wont loose your stuff.