Group Policies prevent install

I previously posted and got great help regarding group polices.

I successfully added a policy for IE. and the did a gpupdate /force. I am now seeing this message from our machines when trying to install an MSI. "The system administrator has set policies to prevent this install". I realize this must be a GP causing this but I did not intentionally set this. I think I might like to keep the policy but I need to better understand it so that some user or admins could do installs. Could anyone advise? I ran rsop.msc on my workstation and saw that there is an entry for Software Restriction Policies but their Status=Not Default Level.

Thanks,

Kevin