IsolatedStorage Exception: Unable to create the store directory 0x80131468

I've been beating my head against the wall for a few days trying to get IsolatedStorage to work on my web server. IsolatedStorage creates a private store for components some place on the web server, which varies depending on the login for the web server process that is used to create the isolated storage. A few of the places that it stores things, although there have been others in different versions of Windows:

• C:\Windows\ServiceProfiles\LocalService\AppData\Local\IsolatedStorage
• C:\Windows\SysWOW64\config\systemprofile\AppData\Local\IsolatedStorage
• C:\Users\www.example.com\AppData\Local\IsolatedStorage

Each time that I tried to write to isolated storage, the code threw an exception System.IO.IsolatedStorage.IsolatedStorageException: Unable to create the store directory. (Exception from HRESULT: 0x80131468). What this told me was that the Web Server process user couldn't create the directory. For once, however, my Google-fu wasn't strong enough to actually solve the problem. I found on the web solutions like: go to the directory (which one?) where it was going to write and give the user (which one?) write permission on the directory, or give the process (which one?) enormous privilege for a little while so the directory could be created. I tried various permutations of these, without success.

Then I notice there is a property in the IIS configuration dialogs that is exactly what I need: Load User Profile, which by default is set to false. This property is found in IIS Manager. You select the application pool that controls your web site, and go to Advanced Settings. After turning this to true, IIS creates a directory for the web site under C:\Users. So if your web site is named www.example.com, it creates a directory C:\Users\www.example.com. When you write the Isolated storage, it is written under there under C:\Users\www.example.com\AppData\Local\IsolatedStorage.