What agent version is it?
What OS is Exchange on- is it 2008?
Try right click- run as admin if it is.
Also check out the FrmInst_computername.log usually found in c:\windows\temp\mcafeelogs\, also the error log and mfeagent.msi.log for clues.
Finally we found the rootcause . due to EMC powerpath environmant variable the MA is unable to generate key pair.
Thanks & Regards