The performance counter "PhysicalDisk(*)\Avg. Disk Queue Length" could not be monitored due to error "0xC0000BB8". Please make sure that the performance counter exists. If you are running a non-english version of Windows then performance counters are named in the language of the Operating System.
This error may be logged by EventSentry when a particular performance counter is unavailable or disabled.
If the counter is disabled, then you can use the Extensible Performance Counter List utility to enable the counter again.
Simply download, install & run exctrlst.exe on the computer where the performance counter cannot be queried.
Once the utility is launched, located the counter in question and make sure that the counter is enabled. If it is not, then check the box.
You can always verify that the counter you want to verify in EventSentry exists by running Performance Monitor from the Administrative Tools.