Windows 7 Fax And Scan Program Won't Recognize Scanner

Windows Fax & Scan program will not recognize my scanner when I try to scan a document to fax. I just installed an external modem to send faxes using the Windows Fax & Scan program, which BTW worked fine when I typed a document and faxed it. If I try to use the Scan feature instead, I get an error window telling me that no scanner was detected and to check my connections. My scanner, which is a Canon 8400F with the Windows 7 64-Bit drivers, works fine on it's own. I am having no luck making it function with the Windows Fax & Scan program.