The startup disk cannot be partitioned or restored to a single partition.

Don't Be Put Off By this Big Wall of Text if you know anything about Boot Camp and Disk Utility Please Help.​

Ok this story starts a while back, I want to get Windows Vista Business on my MacBook so I tried to partition my disk it didn't work I read the Boot Camp guide and Backed Up and Erased my Hard Disk on Disk Utility and restored it and the Partition worked that time.

But when I installed my Windows Vista I needed a different serial number so I gave up on that and decided to delete the Windows partition, what I found out is that the Windows Vista automatically deleted my Mac OS X partition.
Heres where I think somehow I went wrong using Install Disk 1 and Disk Utility I deleted the Windows FAT partition and using the partition tab in Disk Utility I made a new Macintosh HD partition.

So a week down the line I've acquired a Windows XP SP2 disk from a friend and wanted to make a partition for the Windows but when I open Boot Camp Assistant and press continue it reads "The startup disk cannot be partitioned or restored to a single partition."

I've tried erasing the Disk and restoring the Disk using Time Machine a few times and Boot Camp still reads"The startup disk cannot be partitioned or restored to a single partition."

Its infuriating. And I've searched all the forums but this is too specific and so I've signed up here to ask anyone who could help.

Anybody got answers?​

 

Fixed

I took it to a Mac Shop on Sunday for a Genius Bar appointment. They told me how to fix it, but when I got home and started by first making a more than 1 partition, then just one. I realised ever since installing Vista where it deleted my Mac partition, it was formatting the Hard Disk ad MBR and not GUID Partition Table, I surprised they didn't pick up on that. Although I didn't, I suppose.

Thanks for your input Sysiphus.