Tay

I'm not sure if this will help your issue or not but there is a setting in 8.1 group policy that delays logon scripts for 5 minutes to allow for slow scripts. It was causing an issue for us trying to get through our web filter. Students would boot the machine and couldn't get on the Internet for 5 minutes. If you have the latest GPO files the setting is located in Computer Configuration > Administrative Templates > System > Group Policy > Configure Logon Script Delay