By default, the .NET trust level on all shared plans on our Windows 2008/IIS7 web servers are set to "medium trust." Because all sites on these servers reside in their own isolated application pool, you can easily change your site's trust level through IIS Manager, or by making a change in your web.config file.
Changing your trust level through IIS Manager
1. Connect to your site with IIS Manager
2. Double click the ".NET Trust Levels" icon.
3. From the drop down menu, select your preferred trust level.
4. Click "Apply."
Your trust level has now been changed. This change will also reflect in your site's web.config file.
Alternatively, you can change your site's trust level directly in the web.config file
1. Open the web.config file in the root of your site.
2. Add the following line between the <system.web> and </system.web> elements:
<trust level="Full" /> (replace "Full" with your preferred trust level).
*Note, if your web.config file currently has a specified trust level, simply make an edit to the line.
3. Save the web.config file and upload it to the root of your site.
Your trust level has now been changed. This change will also reflect in the .NET Trust Level area when you connect to your site with IIS Manager.