McAfee slows down Vista

Hello,

I got an Dell XPS 420 (about 3 months old) with a pre-installed Vista Home Premium and a pre-installed MC Afee Security Center (Version 7).

Under normal circumstances, I can't work anymore, each startup of Windows Explorer, even each startup of any program is really a pain, because it's so slow, it shows up the performance of a 500 MHz System on my Quad Core Machine. The three browsers IE7, FF and Opera work very slowly.

When I deactivate the following options in MC Afee Security Center, I am able to work with an acceptable performance:
(sorry, I have to translate them from my German version):

• realtime scan
• Spyware scan and scan of potentially unwanted software
• IM scans
• script scans
• buffer overrun protection

I have installed the following components:

• Security Center Build 7.2.147
• VirusScan Build 11.2.121, DAT-Version: 5225.0000, Engine-Version: 5200.2160
• Personal Firewall Build 8.2.118
• SpamKiller Build 8.2.139, Content version: 1068.0.362.362
• Privacy Service Build 9.2.128

The update feature was enabled, MCAfee performed all updates regularly.

Otherwise I didn't install any security software that could interfere with my install of McAfee Security Center (I am aware of the fact that multiple security software installs interfere with each other).

My question: How can I use the above deactivated components without suffering this pertubation (loss of performance)?

I reckon that the performance loss is somehow related to the last patch day in january, I think the problems started there, but I'm not sure.

What I also did (without success concering the above problem):

• I updated my Dell to the most recent BIOS version A03 and to the latest Intel chipset drivers.
• I installed "Spybot Search and Destroy" to see if the lack of performance is related to some Spyware that wasn't recognized by MCAfee. It obviously wasn't and thus I uninstalled it again.
• I followed most of the steps proposed under the boards performance hints

Thanks in advance
Michael