The one main problem you will have is you hard drive is now partitioned. I figure that you system drive/partition is the Vista that came prinstalled so you will not be able to format that partition.
I woudl use Acronis true image to backup the partition that has Vista Business on it to DVD. The use GParted to eliminate all partitions (you can leave th recovery partition if you like) and make one partition for your Vista Business. Then use Acronis and you Vista Business image disk to restore to that partition. Boot to the Vista Business DVD and do a startup repair.
You can backup all your data to DVD and then use the Vista Business DVD to boot from, wipe all partitions and do a fresh install of Vista Business. Warning, if the Vista Business disk is an upgrade disk this will nto work.