Hi there marvin I recently added a used aztech um3100 56k usb dial up modem to my acer laptop ( My build in modem already work thank to your help ) and when i read thru ( limited knowledge only ) i noticed the sentence that said "USB modem not detected by lsusb" but below is the output of issuing lsusb on my system rick@rick-laptop:~$ lsusb Bus 003 Device 004: ID 0c45:6260 Microdia Bus 003 Device 001: ID 0000:0000 Bus 002 Device 002: ID 0a81:0101 Chesen Electronics Corp. Keyboard Bus 002 Device 001: ID 0000:0000 Bus 001 Device 006: ID 0572:1328 Conexant Systems (Rockwell), Inc. Bus 001 Device 005: ID 15d9:0a33 Bus 001 Device 001: ID 0000:0000 rick@rick-laptop:~$ Can you pls help me. Many thanks in advance, marvin