Cannot shrink volume

[stop!theradio]

I'm using Windows 7 Ultimate RTM and I want to shrink ANY of the volumes so I can dual boot with another OS. The problem is, when I go control panel>administrative tools>create and format hard disk partitions, and I select a volume to shrink, I get the "Querying" box for a second and then right after, it says:

"The service cannot be started, either because it is disabled or because it has no enabled devices associated with it."

I know for a fact that virtual disk service is enabled and running. Any idea what it could be? I just need 10-20gb of space for this second partition that I want to create, and I have ample space. Any suggestions?

 

[Lateralus]

There are free tools available that should be able to accomplish this if you can't get 7 to do it.

One that comes to mind: http://www.partition-tool.com/