FAX from a Windows-7 PC via USB FAX modem

Here is one problem I am facing for last couple of days.
I am trying to use a USB dial up/FAX modem in a windows-7 PC to receive/send fax in odd hours. While it was very easy to set up the internal card type in old XP PCs, it seems totally impossible in a windows 7 system. The internal card types are not supported in Win-7 system. So I purchased a USB modem, it was recognised by the system, I followed the standard procedures. But it never worked. Can anybody help?I have watched a lot of videos from Youtube etc. I have followed exactly the same procedures but it doesn’t work.