Microsoft's Brian Keller published a guide about installing the Windows 7 Beta with Virtual PC 2007 SP1

Creating a Windows 7 Beta 1 virtual image (aka virtual machine) is fairly similar to the process you would go through to install the Windows 7 Beta “on the metal” (non-virtualized). But for people who have never used Virtual PC before there are some differences.

Here is how to install the Windows 7 Beta with Virtual PC 2007.

Installing the Windows 7 Beta with Virtual PC 2007 SP1