Might be late, but I wanted to report that after a lot of toiling, I successfully used a modem on VMWare Workstation 10.
The modem is a Rosewill RNX-56USB (Amazon.com: Rosewill 56 Kbps USB Plug and Play Modem (RNX-56USB): Computers & Accessories)
It presents itself as a Conexant USB CX93010 ACF Modem (I think it is using their chipset)
Here are a few things I did.
- Moved the modem to a USB 2.0 port (Never worked on USB 3.0 Port)
- Set my hardware compatibility to VMWARE 10
- VM -> Removeable Devices ->Conexant USB Modem -> Connect (Disconnect from Host).
- On the VM (Goto Device Manager and Scan for hardware changes)
- Modem drivers auto installed.
I have been able to use it to receive faxes, so I'm sure it's working.
I think the key is steps 3 and 4.