You shouldn't have any problem, always that you got a System Builder version and not the version of a specific OEM. If you can't activate Windows through the Internet, activate Windows by calling Microsoft > http://support.microsoft.com/kb/950929/en-us
You won'y have any other problem. Moreover, I don't think you have to remove the Boot Camp partition, as you can erase your OS X partition and reinstall it without erasing the Boot Camp partition
Hi, I have a similar problem but seems like a mirror image of what you had:
I have been using windows on boot camp and have just shifted to OS. getting better at it, but Excel is a huge problem with the keyboard shortcut keys!
I changed around the disk partitions using disk utility to free up and utilize some unused space as the computer was getting slow.
Now I need to get back into windows but the boot camp assistant is not giving me the option to restart using the C: drive. I have data saved on windows that i want to transfer over. Any suggestions please? thanks.