Hello Alpine 
Thanks for your replies. 
So, My DVR is connected  to the modem via a network(no direct cable) and the modem connected by direct cable to my shop pc. 
  
From other pcs  eg my home pc (external IP) I can see the cameras . When I try to see the cameras from my shop pc 'internal and external IP' (which is directly conmnected to the modem etc) I have no visual of the cameras. I get the picture frame of the DVR,  BUT NOT THE CAMERA PICTURES. I have tried with my firewall deactivated but still no luck.Java also downloaded and active x permission. I used web browsers MOZILLA and also INTERNET EXPLORER but  stil no joy! 
  
mikev 
Malta(Mediterranean sea)