agents need admin rights to run

I have backup exec 2012 installed on a win 2008 server.  i am unable to push agents to xp machines and receive the error message: " install failed with error code 1603."

I was able to install the agent from the pc itself under a local admin account with the raw folder.  however since our users do not have admin rights they are not able to run the agent when logged in as themselves.  what is the work around?

I appriciate the help.