From time to time you may encounter errors on a Windows 2003 Server indicating the server is unable to load Dlls related to performance counters, performance counter data is missing, or performance counters are corrupt.
To resolve this issue you can either attempt to restore just the performance counter in question ot repair all performance counters installed on the server.
To repair all performance counters:
Open a Command Prompt and type the following commands
cd \windows\system32
lodctr /R
To repair only select performance counters:
Open a command prompt window.
At the command prompt, type cd %Systemroot%\System32, and then press ENTER.
At the command prompt, type findstr drivername *.ini, and then press ENTER.
Review the list and note the driver name and inifile for the performance counter that you desire to reload.
At the command prompt, type the following line, and then press ENTER:
lodctr inifile
where inifile is the name of the .ini file for the driver that you want to reload.
Restart your computer.
Source: http://support.microsoft.com/default.aspx?scid=kb;EN-US;300956