Speed-up Modem and Serial Connections
Windows is normally limited to a default maximum speed of 115,200 bps for serial communications. By using compression and high-speed UARTS modern modems may reach this limit and not be allowed to operate at full speed. This tweak allows Windows to communicate with speeds of 230400, 460800 and 921600 bps.
Open your registry and find the key below. If you have more than one modem there will be multiple sub-keys 0000, 0001, 0002...000x representing each modem. Check under each sub-key until you find the modem you want to speed-up then continue with the step below.
Make a backup of "Properties" value before it is modified. Then double-click on "Properties" and notice that the 51st, 52nd, 53rd and 54th digits will currently show "C2 01" or "84 03". Highlight these digits and then change them to "10 0e", do not change any other digits.
Click OK and exit the registry editor.
Settings:
System Key: [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\0000]
Name: Properties
Type: REG_BINARY (Binary Value)
Note: Once enabled open Control Panel -> Modems -> Your Modem -> Properties -> General and set the required maximum speed.
Note: Some older slower modems may not be able to operate at these speeds, if your modem experiences problems switch back to a lower speed.
Open your registry and find the key below. If you have more than one modem there will be multiple sub-keys 0000, 0001, 0002...000x representing each modem. Check under each sub-key until you find the modem you want to speed-up then continue with the step below.
Make a backup of "Properties" value before it is modified. Then double-click on "Properties" and notice that the 51st, 52nd, 53rd and 54th digits will currently show "C2 01" or "84 03". Highlight these digits and then change them to "10 0e", do not change any other digits.
Click OK and exit the registry editor.
Settings:
System Key: [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\0000]
Name: Properties
Type: REG_BINARY (Binary Value)
Note: Once enabled open Control Panel -> Modems -> Your Modem -> Properties -> General and set the required maximum speed.
Note: Some older slower modems may not be able to operate at these speeds, if your modem experiences problems switch back to a lower speed.