Had another adventure with an install of Exchange 2010 SP3 tonight. Things were humming along fine until the Hub Transport Role update started and after watching the bar hardly move for 30 minutes, I started getting antsy. Task manager was showing almost zero CPU usage.
A quick check in the eventlog showed a bunch of LoadPerf erros with EventID 3011 and 3012. The exchange install log showed a bunch of errors trying to load performance counters, failing each one 4 times with a 15 second delay between each attempt:
“The definition file for category ‘xxx’ is in use, the process will retry in 15 seconds…”
Microsoft has some suggestions here but I hit it with a quick lodctr /r from an elevated command prompt and the service pack step finished within a minute.