If you have not already done so, you might want to download Process Explorer (free from Microsoft) and once you have it launched right click in the columns listing to add the Image Path column. This will show you the distinct pvxwin32.exe process that the web engine is running (you will see the path to the webeng directory) as opposed to those running for MAS 200. Turn off the web engine and make sure all of the web engine specific processes actually die off. If not you can right click on the remaining processes and manually kill them. Then restart the web engine. We have found that sometimes not even a server reboot clears a hung web engine process but Process Explore can always kill them off.
