Quick links

General modem information
Modem standards
AT command strings

After exiting Windows, I receive 'CTS signal is not responding' when attempting to use Q-Modem:

This is generally caused when the modem is not being initialized. To initialize the modem, type the below commands at the command prompt.

CD\QMODEM
DL D192PRO.CLI
QMODEM

General modem troubleshooting:

See our general modem troubleshooting page which lists complete information on computer modems.