I perform Exchange Best Practice Analyzer on a few servers but 3 servers failed on the following errors. Exchange server: Performance data cannot be accessed. Cannot collect performance monitor data from server. This could be the result of a network or permissions problem. Error: Unknown error (0xc0000bb8). Have tried this URL http://technet.microsoft.com/en-us/library/aa996089(v=exchg.65).aspx But does not help. Need some advise. Many thanks. Kelvin Teang

Check FQDN is pinging for the right ip address (Check is there any wrong host file entries , C:\windows\system32\drivers\etc\hosts , open in notepad ) Check for Remote Registry Service , Make sure its running in Source and target servers --- There is one more common issue , running from Exchange 2010 to Exchange 2003 --- or Try runnning from some other machine. Satheshwaran Manoharan | Exchange 2003/2007/2010 | Blog:http://www.careexchange.in | Please mark it as an answer if it really helps you