Well the simple solution that fulfils all your heart’s desires is to:
- save any data on the suse install (like files in /home/yourname/docs or music or whatever) – maybe put them temp on the big drive.
- pop in the windows install CD and install windows. When you see the win partitioner, delete all the suse partitions. Then make one partition of any size that suits you on the 500 drive for win and install it, leaving the rest of that drive for Suse, unpartitioned, empty.
- pop in the openSUSE installer and let it have it’s head with the empy space on the 500 drive.