I don't understand why WUG Premium doesn't allow you to set thresholds on the performance monitoring data for sending alerts, but this seems like a common complaint so I'll leave it alone for now.

I found the WMI active monitors and I have been successfully using the Logical Disk / % Free Disk Space monitors with my Windows 2003 servers.  This was working really well until I decided to set them up for a new file server we installed that is based on Windows 2008.  I was getting a "down" error on those monitors because the value returned for % free space was around 1%.  It looks like Microsoft acknowledges this is a problem in KB949701 and instructs users to refer to another WMI property to retrieve that data instead.

"To work around this problem, use the PercentFreeSpace property of the Win32_PerfFormattedData_PerfDisk_LogicalDisk WMI class."

It looks like the property that WUG calls is PercentFreeSpace_Base of the Win32_PerfRawData_PerfDisk_LogicalDisk class, which is the correct property for all other Windows operating systems (except Vista, which has the same bug).  Is there a way I can define a new WMI monitor in WUG that uses this PercentFreeSpace property of the Win32_PerfFormattedData_PerfDisk_LogicalDisk class instead of PercentFreeSpace_Base for Windows 2008 servers?