As far as I know Windows Easy Transfer does not transfer installed programmes and in any case, during such a complicated procedure such as this I would think it advisable to uninstall McAfee from XP first, then reinstall it in 7 afterwards.
I trust the 7 upgrade is actually to Windows 7 SP1? (Including Service Pack 1)? Once done apply all updates from Microsoft except perhaps things you may not need like Bing, up to you of course, but very important even if you don't use it, upgrade Internet Explorer to version 11. (Once SP1 is installed).
McAfee relies on it to function even if you use another browser by default..