How can I change the account used for the QOS service?

Create a new account called “ACSService” (ACS for Access Control Service) and add it to the local Administrators group. When adding ensure you set the option “password never expires” and unselect the option “user much change password at next logon”

Start the Computer Management MMC snap-in (Start – Programs – Administrative Tools – Computer Management)

Select the ‘Services and Applications’ branch

Select Services

Right click on ‘QoS Admission Control’ and select Properties

Select the ‘Log On’ tab

Select the ‘This account’ option and select the ACSService account, enter its password

Click Apply then OK (when clicking Apply the account will be granted the ‘Log On As A Service’ right)