Hi there
1) This is a W7 Forum -- so if you want help I'd suggest you phrase your post a little differently -- nobody forces you to use it and if you don't like it that's your rightful) privilege -- however a lot DO like it and run it successfully.
2) Since we are all reasonably nice on this Forum here's what to do.
3) Since you are obviously comfortable with Linux download the Live GPARTED CD from here
GParted -- Live CD/USB/PXE/HD
4) boot it up and delete all your W7 partitions -- better off actually delete all the partitions, re-format the disk again
5) install what ever OS you want to install. XP, Linux Gentoo, Debian etc etc.
Cheers
jimbo