I'm wondering why you want to buy a Modem. Are you stuck using a Dial-Up connection to connect to the internet? If so, I'm so sorry, and know that all of us here feel your pain. The HP Printer that you have connects to the computer Via USB, the Fax part connects to a Phone Line from the wall. The Phone Modem in the Fax Machine is all that is required, besides a Phone Number assigned to the line you plug into it.
I wanted to clarify that because I somehow think you are under the impression that you need a Dial Up Modem in your computer for the Fax to work, if not, then I'm sorry for thinking that of you.
To answer what you were plainly asking:
Agere Software base Modem Design
Windows 7 Readyhttp://www.newegg.com/Product/Product.aspx?Item=N82E16825164003
In case the Drivers that come on a CD when you order this part from Newegg do not work, here
a link to Download the drivers directly from the Rosewill website.
Edited by s1lents0ul, 16 December 2010 - 10:29 AM.