Latelly i faced a problem migrating Windchill version 9.1 among its maintenance releases.
During the upgrade process, quite at the beginning, there is a step where the PSI try to stop Apache and Tomcat (even if they are not running).
Tomcat stops ok, and Apache (running at port 80) also stops, but the PSI thinks it is still running, and we could not continue with the upgrade process.
We found that the problem was caused by the Antivirus (ESET NOD 32), that has a service running that cannot be stoped from the services management UI.
It was not enough to stop it, it was necessary to completelly remove it from the server (uninstall), in order to proceed with the upgrade process.
After the upgrade was successfully completed, we installed it back again.
Just let you know, i think it might help.
Saul Szulanski
One1
