Question: Where would the physical files be?

Answer: 
I've also seen it under `%ProgramData%\IsolatedStorage` (so often C:\ProgramData\IsolatedStorage).

This particular case was a Windows Server 2008 with IIS site-related data.
When accessed/created by a system account, I found the folder here:

```
C:\Windows\SysWOW64\config\systemprofile\AppData\Local\IsolatedStorage

```