I agree with Mick, there are much better suites around than the McAffe offering. Grab the removal tool listed here
http://www.technibble.com/repair-too...-removal-tool/
Then you are free to choose what you put on. If your behind a router then the windows firewall (especially Vista/7`s) coupled with a decent AV such as Avira/Avast or even Microsoft Security Essentials should.
You should notice a speed difference when you remove McAfee, it really is one off the worst suites on the market, allthough detection wise it`s not bad with Artemis.
I think the "optimised for Dell" is a complete load of tosh honestly. It will still use the same resources, I/O, etc.
Good luck.
p.s. If you are going to go paid then Norton is now a much better product as is the latest Kaspersky.