Symptom: Cannot install the web agent after a previous installation has been removed.
You might have an existing installation of the web agent.
You might have a previously-installed web agent and did not use the web agent’s uninstallation program to uninstall the agent.
The installation program’s productregistry file might be corrupted.
Possible Solution: To resolve the issue, manually remove the web agent as explained in the following task description.
Stop all of the web sites.
Stop all of the application pools.
Remove Agent for Microsoft IIS 6.0.
Remove entries from product registry
Remove the PolicyAgent-base directory from the server.
where PolicyAgent-base represents the directory in which the web agent was originally installed.
Remove the following entries from the PATH variable:
Restart the server.