With Avast installed, Win7 64bit crashes when starting Virtual PC in VPC 2007

I recently uinstalled Avast Free from my PC since it was causing my NIC to reset itself every few minutes. It took me a while to figure out it was Avast that was causing it because I never experienced any problems with Avast before. I then noticed there was a new version of Avast Free so I installed that. I did not experience any problems with my network so I was happy again. But today I started Virtual PC 2007 and whenever I tried to start a Virtual Machine, Win7 would hang and my only option was to reboot my PC. Again it took me a while to figure out what was causing this, but as it tuns out, it was Avast (again). If I uninstall Avast, VPX 2007 runs perfectly. Installing Avast and VPC 2007 hangs whenever I try to start a Virtual Machine.

So what could be wrong? Any tips getting Avast and VPC 2007 working together?

Thanks in advance.

Disable hardware VM and see if that solves it.

Thank you for your reply! Had tried that already. Didn’t make any difference.

Also tried with the the behavior shield disabled ?
Also tried with hardware acceleration disabled ?

Yes (even disabled all shields).

Also tried with hardware acceleration disabled ?

Yes.

Both made no difference.

Anyone any other ideas?

I thought you meant disable hardware acceleration in VirtualPC (which made no difference). I was unaware there was a “Hardware Assisted Virtualization” option in Avast. I disabled that and now I can start my Virtual Machines just fine!

Is this related to this?