Obviously you are expected to follow a legal license progression, meaning the upgrade requires you own an XP or Vista license but they do not have to be installed. Many people like to format the hard drive first. Then you use a double install: Run through the installation once. Then reboot and install again. Then activate. On rare occasions it takes a third install.
It may be a driver that monitors your battery or something along those lines. The two biggest causes of BSODs are viruses and out-dated drivers. Fresh install pretty much rules out virus so you definitely want to check out your drivers.
Bonjour comes to mind as a service that worked fine in Vista but caused issues in W7 so, since it came from Vista, see if you have Bonjour on there and if so, uninstall it.