N 360 V6 - Another download manager is currently running

Purchased and followed the download instructions for 360 v6

Seem to have 264 Mb of 360 files downloaded onto C drive, but my account still shows that it is not installed

 

When I click on the Dorton Download Manager icon it tells me that 'Another downlaod manager is currently running'

 

The PC still has Norton Internet Security running - not sure if this effects things.

 

Any advice?