>I just upgraded my Virtual PC 2007 installation to VPC2007 SP1. The
>installation of the new system appeared to be successful. My host is
>Windows XP SP3. I then booted my guest (Vista, no service pack) and all
>appeared normal. Next I installed Virtual Machine Additions in my guest
>figuring that I should update the Additions along with Virtual PC (I had
>the Additions from the old version of Virtual PC installed previously).
>
> Now, alas, my guest is nearly unusable. It is extremely slow and Virtual
> PC consumes 100% of one of my cores (my host is a dual core machine). It
> certainly appears that Virtual Machine Additions is at fault because the
> guest ran fine before I installed the new version of the Additions.
>
> What should I be looking at the hopefully fix this problem? Uninstalling
> Virtual Machine Additions doesn't seem like the right answer even if it
> works.
>
> Peter

> Don't upgrade the Vista guest until it is at service pack level one.
> Until you do reinstall the vmadds for VPC 2007 rtm. If you need the
> vmadds .iso for VPC 2007 rtm you can download VPC 2007 from
> http://www.microsoft.com/downloads/details.aspx?familyid=04D26402-3199-48A3-AFA2-2DC0B40A73B6&displaylang=en
>
> and install in a vm. That will extract the vmadds.iso. Naturally, VPC
> 2007 won't run in a guest but it will install and that is the easiest
> way to get the .iso.