I'm probably the least techie minded member to answer you but I had McAfee pre-installed on my laptop and it was a pain. I decided to uninstall it using the built in option but after I had done so and I tried to install Avast I kept being told that I still needed to uninstall McAfee. I ended up using the following link which sorted the problem immediately.
http://download.mcafee.com/products/...tches/MCPR.exe
I also kept a note of the following advise, though in my case I didn't need it.
Sorry I can't give you a link to the site I found the above on but I just made a note of the instructions and not the site address.
