Get"no fax application found"with highspeed internet external modem/box

Sorry,I'm French! So that means,in the context of that forum. . . , that I don't actually handle the English technical vocabulary of what has to do with computers (I don't actually do in French either anyway !)So be kind on me, use simple terms with many extra explanations ! My problem is: I had not try to use my fax with my AIO 922 since I got high speed internet which comes through an external modem called "box" over here (same over there?) supplied by my access supplier (whatever you call it)club internet, not to name it. So that the internal original modem has now been set aside and is no longer used in the connection to the net. Plus I guess something may have changed in the setting (? = configuration) of my internet data. Plus the Internet connection is not any longer a direct one, but a home/local area network one (does that make any sense? !) So now when I try to run the fax, I get that error message "No fax application found" and, in the right-hand bottom corner of the "fax console", you can read "no printer connected". But the printer is definitely found by all other applications (copying/scanning/etc. . .)So the printer IS (properly?) connected. I have uninstalled and installed again the whole AIO Dell software with the install Dell CD (sent with the printer) at least 3 times but it won't work. What else can I do??? Thanks ever so much, as "they" say. Ragnagna.