Sure you can.
Sign out of, then exit MOC.
Use Windows Task Manager > Processes tab to locate cucimoc.exe. Right-Click on it and choose 'End Process Tree'. This kills cucsf.exe as well.
Use Windows Explorer to navigate to the User's Profile. Assuming Windows XP, find C:\Documents and Settings\[User]\Local Settings\Application Data\Cisco\Unified Communications\Client Services Framework\Communications History folder and delete ConversationHistory.xml
You may want to delete MOC's GalContacts.* from C:\Documents and Settings\[User]\Local Settings\Application Data\Microsoft\Communicator\sip_[sipuri] folder while MOC is stopped. Be aware though that GalContacts.db and .idx only get regenerated on a PC at a randon period up to 60 minutes are sign-in. MOC may not be entirely happy until you can see the GalContacts files back in that folder.
Restart MOC
Start the CUCiMOC Conversation Pane manually from the MOC menu
Smile.