I had a dual boot system but decided to remove OpenSuse for the time being. I deleted the partitions containing OpenSuse using GParted and set Vista (soon to be upgraded to Win 8) as boot.
How do I remove the dual boot that remains (see attachment). Its a strange because its asking to install OpenSuse, but there is nothing to be installed.
You still have the Grub boot loader in MBR, the first sector of your hard disk. Use a Windows repair disk to rewrite a generic boot code in MBR. Then you won’t see this screen anymore.
I don’t know about other rescue discs. You should be able to create a Windows rescue boot disk from any Windows installation on another computer installed with the same version. If you’re thinking of dual-boot systems, bear this in mind in future! But of course hindsight is always 20/20. If you are able to find a rescue disk, you may find the guide (for Windows 7, but it’s similar) for recovery in How to Fix Windows 7 When It Fails to Boot .
In the meantime, if you’re going to upgrade to Windows 8 soon anyway, you’re best bet is probably keeping GRUB until you do. And while you’ve still got Vista, you also may want to keep the installation of a sensible operating system on your hard drive :).