After a long time, I spent some time profiling one of the web apps I was working on and I bumped into some basic startup issues with the Performance Analysis tool i.e. Profiler. Here is a cut-to-the-chase version.
The first issue was:
The web site could not be configured correctly; getting ASP.NET process information failed. Requesting 'http://localhost/StarterSite/VSEnterpriseHelper.axd' returned an error:
The remote server returned an error: (500) Internal Server Error.
PRF0017: Can't launch server for 'http://localhost/XXXXXXSite/'.
Solution: If your virtual in IIS is mapped to a folder which is under SourceControl, the files may be read-only. Give write access to the web.config file. When VS Profiler runs, it modifies
the web.config file to insert certain configurations on the fly that enables VS to profile and attach to the w3wp.exe process. If the file is read-only, I found out that it barfs with this error.
The second issue was:
PRF0010: Launch Aborted. Unable to start vsperfmon.exe
Solution: Add %VSINSTALLDIR%\Team Tools\Performance Tools to the user path and system path.
With these two basic issues resolved, I was on my way.
If you still have issues, go to the MSDN Forums and search for your issues. One of the threads that helped me is: