If the issue persists across restarts of Webpi there is another issue that occurs when we cannot read the performance counters on the system during startup.
To identify this check the Application and System Event logs for Perflib or Microsoft-Windows-LoadPerf errors. If you see these errors then the only current workaround is to fix the counters per the following links.
Windows 2003/ XP
http://support.microsoft.com/default.aspx?scid=kb;EN-US;300956
Window Vista .
1.Click Start, expand All Programs, and expand Accessories.
2.Right-click Command Prompt, and then click Run as administrator.
3.At the command prompt, type lodctr /r, and then press ENTER.
Reference : http://technet.microsoft.com/en-us/library/cc774958.aspx
Please post back if there are further questions.
Thanks
Richard