get a windows 98 boot disk and boot to it
do fdisk, deleate all the suse partitions, create some windows partitions
then restore the master boot record with
then install windows as normal.
If that doesnt work, you can go to the website for the drive, and download their utility package. boot of the drive manuf's disk, and do a "write disk pack" or "low level format" This is much more time consuming, but it will COMPLETLEY overwrite and deleate everything on the drive.
good luck, and have fun setting up your shiny new dual boot winxp pro/slackware 10 system