How to increase virtual hard drive space

Solution 1:

With the VM turned off, attach the virtual hard disk VHD file by doing:

Right-click "My Computer" > Manage > Storage, right-click "Disk Management" and choose "Attach VHD".

You should now be able to resize the virtual disk as if it was a local disk.

Solution 2:

If I recall correctly, Virtual PC 2007 comes bundled with an application to resize VHD files. I'm not sure if VPC 2009 does, but if not, you can download v2007 for free from Mcft's website/

Solution 3:

Shut down the virtual machine and go to its settings/configuration panel. When it's running certain things cannot be configured like hard disk size, RAM allocation, etc.

If it's a limitation of the product enforced on per disk size try added a second virtual disk.