Internet speeds are slow when connected to Direct TV HD DVR

How is your DVR connected to your home network?

Confirm that your DVR is connected to the same sub net as the rest of your network.  If it is, then a reconfiguration would be in order but we need to know if you are connected by Ethernet cable or wireless, and if wireless the brand name and model of the wireless adapter.

Im connected by an Ethernet cable. Not sure about the sub net how do I tell?

Motorola Modem SB6121

Apple Airport Extreme Version 7.6 n,b/g compatible, connected by ethernet

What are my next steps?

If this stuff interests you , you can always do a Google and educate yourself as to home networking, IP addresses etc. You can press and hold the info button on your HD DVR and then select more system info. Scroll down and it will indicate the IP address for the DVR. It will typically be a number such as 192.168.1.106. The single "1" indicates the sub net and all devices should have the same number in the same spot. The last 3 digits will be different on each device. To check the IP address on your computer and router on your computer click open -> in the search box type cmd then type ipconfig in the black screen.  The resulting screen will list the IP for the computer and the default gateway. All should have the number 1 in the noted location.

If they all have this, run a reconfiguration of the system thus:

Connect the Ethernet cable to the top or only port of the DVR and an open port on the router. Check that the router has DHCP enabled (essential). Do a red button (inside card door) reset of the DVR. When it's booted up, do thus: Menu -> .....setup -> system setup -> network setup -> restore defaults.At this point stop and go to your router and disconnect AC power for a minute and plug it back in. When all the lights settle down, go back to the DVR and run the "connect now" command. You should get a "connected to Internet" message.Allow 24 hours for the system to download then try downloading a concert from channel 1239 as a test.