What is Load User Profile in IIS 8.5?

Specifies whether IIS loads the user profile for an application pool identity. When set to True, IIS loads the user profile for the application pool identity. Set to False when you require IIS 6.0 behavior.


This is great for application isolation.  It also can have an impact on your application if you are using Active Directory to manage application access.  The Windows Cryptographic Service Provider will try to store or load a key for your certificate in the user store, and this will require a profile to be available; otherwise, a cryptographic context error will occur.


Note that the Load User Profile setting only applies to user accounts. Service Accounts like NETWORK SERVICE and ApplicationPoolIdentity have special handling.

Source

http://stackoverflow.com/questions/17149132/what-exactly-happens-when-i-set-loaduserprofile-of-iis-pool


https://technet.microsoft.com/en-us/library/cc745955.aspx