<p>Hey everyone, I'm using Virtual PC and working with a virtual hard disk (*.vhd) that is only sized at 8.2 GB. I would like to double the size to something like 16-20GB. I see options for compacting the VHD but nothing to expand it. It's set to "dynamically expand" but I'm installing some software and it doesn't seem to resize itself to a larger space.</p>

<p>Thanks much.</p>

Never worked with Virtual PC but from other virtualization software I know I guess that dynamically expand means that initially the .vhd file will take less space in the HD than the specified and will dynamically grow as you keep installing programs or adding files into the virtual drive UP TO the specified size.
For what you want I guess that you will have to modify the specified size in the virtual hard drive from Virtual PC's setup window.
A bit offtopic but give a go to Virtual Box: www.virtualbox.org