ServletExec 4.1.1 is the first version of ServletExec that has been successfully tested on Windows XP using IIS.
Newer versions of ServletExec support Windows XP also.
However, there is a Security Options configuration change necessary in order to allow access to the Security tab for setting correct file permissions on the ServletExec ISAPI folder.
From the Control Panel, navigate as follows:
Administrative Tools - Local Security Policy - Local Policies - Security Options
Note that it may be neccessary to view the Control Panel in "classic view" in order to see the Administrative Tools.
Then double-click the Policy named "Network access: Sharing and security model for local accounts."
Change the Security Setting to: "Classic - local users authenticate as themselves."
Now, when you right-click on the ServletExec ISAPI folder, and choose Properties, you should see the Security tab.