
your outlook throw the above error when you click an hyperlink in your outlook message, there is nothing to do with the group policy eventhough the error looks like gp mismatch..
This error comes when your system get confused about the default browser of your windows. There are two locations you need to look at...
Set IE as your default program
To set IE as your default program, go to Control panel > default programs > set your default program. Then click on internet explorer and click on set this program as default.
Restoring REGISTRY settings to default
After setting up IE as your default browser your need to restore...