Trojan,worm or virus?

[bchivers]

I have been battling a problem for 2 weeks. I am not able to access some web sites, when I turn on

McAfee my color quality goes from 32bits to 8bits and back when I close Mcf. I am unable to get

updates from windows update, Mcf.virus scan and anti-spyware, AVG.pro. Cpu sometimes runs slow and

a few other settings changed. I have updated ad-aware and spy-bot,even run an online scan from Mcf.

Is this a virus,trojanor worm and what else can I do.I am beginnig to get desperate.Any help will

be greatly appreciated. TIA. I have a 1.2gb celeron 512mb ram win.xp home.

[NeoNemesis]

Are you sure your McAfee is compatible with Windows XP, check that out.

[bchivers]

I have used it for over a year without any problems.Even with it turned off the other problems still exist.