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.