This is the Windows driver for the Zoltrix "Rainbow" (not sure) modem.
It is a fair good 56K modem, the problem is that he doesn't use the correct sequence to compose the phone number. You have to use ATP*T instead of ATDT to compose.
This driver allows you to use the modem as a normal modem with Windows. If you use AOL, you have to manually modify the compose sequence in the advanced configuration since AOL doesn't use the Windows drivers database.