Uninstalling windows 7 upgrade and Vista then reinstalling both back into the compute

If you're going to reinstall, I'd forget about uninstalling, and just wipe the partitions of both W7 and Vista (assuming the "W7 upgrade" hasn't taken the place of Vista, that is, in which case you'll only need to wipe the partition of W7), then reinstall Vista to one partition, and W7 to another. If an entry for the latter system installed isn't automatically added to the boot menu by the installer (normally it does add it), then get EasyBCD 2.0, and add the entry you lack, being sure to point it at the partition that the system you're trying to load is at.