Symantec Enterprise Vault Add-in
Just a helpful FYI that I found. I am running Windows 7 Enterprise 64 bit with Office 2013 installed. I installed Office 2010 then upgraded to make another program work, but I noticed that my Enterprise Vault add-in was not showing in my outlook. After trolling the forums, I found a few references to Valkyrie.dll. I searched my C: drive for that particular .dll file and found many results, but only 1 with that exact name. If you run that file using c:\windows\system32\regsvr32.exe it will register that .dll file. You will see all of the results disappear from the search and when you restart outlook, the add-in will be there and be working correctly. Hope this helps.
For what its worth, if you run C:\Program Files (x86)\Enterprise Vault\EVClient\ResetEVClient.exe , this will achieve the same result as well.... also I've seen where the mapisvc.ini gets updated for outlook too, removing the EVMSP reference needed for Virtual Vault and Vault Cache to work correctly, EVResetClient.exe also resolves this issue too