There are three ready answers to ‘how often does group policy update?
- COMPUTER CONFIGURATION and USER CONFIGURATION changes automatically refresh every 90 minutes with a random offset of upto 30 minutes
- When you run gpupdate /force
- When you reboot
All three of these assume you are on a single server domain. If you have multiple servers you need to also add the time it takes to replicate the changes to the DC closest to the PC in question. The default refresh times can be changed… also through Group Policy, see: Computer Configuration, User Configuration .