Currently have Satellite internet, now DSL is available and I am installing it. I have it installed successfully on the desktop. We have connected the router we were using with satellite and it will not work as is. I am assuming it needs to be reconfigured, but I have no idea how to do that. Can someone help?

Can someone help?

Post the router and any other equipment brands and models and someone familiar with those products may respond. Nobody is going to guess at what you have.

A very general high level overly simplistic overview of some possible things that may need to occur is:

Change router's external (WAN) interface card/port to match media format in which the DSL service is delivered (Ethernet (http://en.wikipedia.org/wiki/Ethernet)?)
Access router's administrative interface via web browser or telnet, and reconfigure external router interface to match parameters used by DSL telco:

Protocol used, PPPoE (http://en.wikipedia.org/wiki/Point-to-Point_Protocol_over_Ethernet) or PPPoA (http://en.wikipedia.org/wiki/Pppoa)
PPP username and password
VPI (http://en.wikipedia.org/wiki/Virtual_Path_Identifier) and VCI (http://en.wikipedia.org/wiki/Virtual_channel_identifier) numbers
IP addressing (http://en.wikipedia.org/wiki/IP_address) assigned to you

Secure router against unauthorized remote access.
Work around any MAC address (http://en.wikipedia.org/wiki/MAC_address) filtering or other strategies employed by the telco to limit or prevent use of multiple computers per DSL connection, 3rd party equipment not supplied by the telco, or enforce the purchased service plan.

I have a Satellite Internet connection at my place in the country and cable Internet at home. My Satellite connection uses a fixed IP address and not DHCP.

Yours may have also been configured with a fixed address. If changing your WAN port to DHCP and rebooting the router does not do the trick then the easiest way to overcome a previous configuration that no longer applies is to reset your router. Reconfigure it using your quick setup guide that came with your router.

Before resetting your router, make a note of all of your current settings such as your wireless security configuration.