I don't think the "Apple Built-in iSight - Unprorammed" thing has anything to do with Parallels at all. Exactly the same thing happened to me with my first XP-SP2 install on Boot Camp (MacBook Pro 17"). I initially installed Boot Camp 1.0, before there was any support for the iSight, and then each of the new Boot Camp updates. When iSight was finally supported, there it was! "Unprogrammed", and, of course, it wouldn't work. It just happens that I have a son, and I got an iMac for his birthday about that time. He, too, installed XP-SP2 on his Boot Camp, and the iSight was installed perfectly at the first attempt. I concluded that the problem was in the previous history of installations on XP, particularly in the previous installation of Boot Camp drivers. I looked up this problem on the Internet, and, sure enough, I wasn't the only case.
What did I do? Well, I simply destroyed my Boot Camp partition, recreated a new one, reinstalled XP-SP2, plus Boot Camp, and, voilà, iSight was working.
I think your case is similar, even if running on a VM. It will be difficult to solve the problem otherwise. And, most definitely, it is a Windows problem. Parallels has nothing to do with it, IMHO.
Best.
What did I do? Well, I simply destroyed my Boot Camp partition, recreated a new one, reinstalled XP-SP2, plus Boot Camp, and, voilà, iSight was working.
I think your case is similar, even if running on a VM. It will be difficult to solve the problem otherwise. And, most definitely, it is a Windows problem. Parallels has nothing to do with it, IMHO.
Best.