Unable to update guest OS hard drive size

I am running VMWare Fusion 6.0.4 on OS X 10.10.3. I have Windows 7 as the guest OS. Originally I had the hard drive set to 60GB. It was running out of space so I increased it to 100GB. However, Windows 7 still thinks there is only 60GB on the C: drive. Fusion thinks there is 100, on the Windows side, in disk management, Disk0 is listed as 100GB, but the C: volume is 60GB and the option to extend it is greyed out. How do I get my 40GB to be recognized?

There is lots of useful information in this VMWare Knowledge Base Article:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1004071