The steps given below will help you set up a dedicated IIS Application Pool using Plesk 10 control panel.
1) Login to your Parallels Plesk Panel using your username and password.
2) Click on the Domains link located on the left panel.
3) Click on then Control Panel link situated on the right side of the relevant domain name.
4) Click on the More link located under Websites & Domains.
5) Now click on the Dedicated IIS Application Pool link.
6) The final step is to click on the Switch on button. This will enable a dedicated IIS application pool for your chosen site.
That will do the trick!
