The confusing thing I found is the part that says..
"problem is, i have no disks, as they didnt give me any, so will have to buy something.
recovery disks wont work will they?"
So are you saying you do have the recovery disks or you don't have any disks?
Also depending on the brand of the machine you may not need the number from the sticker if you have the recovery disks as certain brands will enter it automatically (dell and HP for a start) when you run the recovery.
I would echo what everyone else is saying though, why on earth would you want to go from windows7, which works well to Vista, which is the largest pile of rubbish MS have ever called an operating system (apart from maybe ME)