I somehow downloaded and installed the 4.02 version of the agent. Now when I try to "Edit computer Settings" from the Dashboard it tells me I have the incorrect version and that I should upgrade. 

My question is can I just run the newer version on this server while I leave the 4.02 version on it or do I have to uninstall the old first?

You can either uninstall the old version and install the new one, or use the mobile client to upgrade your agent by tapping on the agent version and selecting upgrade or by waiting up to 24 hours for the agent to auto update itself (if not auto updates were manually disabled).

All set...thanks.

Another question.

From the 'Dashboard' I clicked on 'Web Application'. It takes me to the log on screen but after I enter my u/pw it just sits there...never really opens anything. What do I need to configure? 

Can you please try to use a different browser? Also are you using the latest version of flash player? If the problem persists ask here http://forum.pulseway.com/forum/35-web-application and a support representative will respond.