I did find a third party article in which people have found a solution:
Hide Local Disk (Q:) added by Office 2010 Beta
I hope this helps! (you may want to
Back up the registry first)
Modifying REGISTRY settings incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of REGISTRY settings can be solved. Modifications of these settings are at your own risk
Lisa
Microsoft Answers Support Engineer
Visit our Microsoft Answers Feedback Forum and let us know what you think.