If you have installed Windows 7 on your MacBook bootcamp partition and you also run the partition on Mac OSX with VMWare fusion then you will have windows activation problems.
Windows 7 will see your partition install and VM as two separate machines. So if you activated Windows 7 on your VM this will be your genuine copy and when you run Windows 7 from your partition you will get the message, “This copy of Windows is not genuine.”
When a copy of Windows is not recognised as genuine it prevents you from getting online updates. It also prevents any other Microsoft programs like MS Office from performing updates.
The simple solution is, as it is essentially the same install, you run all your updates from the activated machine. In the example above, you can run Windows update and office update from the VM and that will be replicated across both machines.
UPDATE: You can also call Microsoft and advise them of your configuration. They will happily provide you with a separate activation code for the install that is not activated. A much cleaner solution.