Windows 7 - Freezing Issues - Help Please...

I bought an Acer Timeline 5810TG in August with Vista installed and everything was great. Then I think I opened an infected email and it started freezing with the only option to turn off and start again. Didn't reinstall as I knew my windows 7 upgrade was coming. Clean installed Windows 7 but after a while had same freezing issue. Uninstalled AV and the freezing began in seconds! AV seems to keep the problem in check but it still freezes after an hour or so. No scanning tool I've used throws up any concerns (Threatfire, Spybot etc) Have clean installed again but not transfered previous data over just in case but same problem - I need help...Please...

Have you run malwarebytes? If this is a rootkit virus I use unhackme. It usually resolves the issue but you have to be careful in what you delete. It comes in a fully functional trial version.

I definately haven't tried the second one, I'll search it out and let you know how I get on; Cheers Roban...