I have a Conexant CX11252-11 Modem.
I only found driver for XP, is there a workaround for Win 7 x64, or perhaps I should throw away this modem?
This is some really old software modem. Conexant doesn't seem to provide 64 bit drivers.
Best would be to buy some new hardware modem (like Rosewill Rnx-56usb which usually have way better driver support (or don't even require any additional as they're primarily an USB-serial port interface with attached serial modem).