Exchange 2010 Database Dismounted, Corrupted

Check if your .edb files are not locked by your local antivirus (btw that can also be the cause of the corruption)

I found also move the file to a different hardrive in case the corruption is hardware related.

You look here: http://forums.msexchange.org/m_1800600673/mpage_1/key_/tm.htm#1800600673