Data type Range Default value
REG_DWORD 0 | 1 1


Determines whether FIFO (first in, first out) buffering is enabled. This entry is effective only when the system includes hardware that supports a FIFO buffer, such as the National Semiconductor 16550AFN.

Value Meaning
0 Disables FIFO.
1 Enables FIFO.

Note Image Note

The value of this entry is used as the default value for all serial ports on the computer. Settings for specific serial ports are stored in the device-specific subkey for that port in the Enum subkey (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum).

Tip Image Tip

To change this value, you must edit the registry. To change the ForceFifoEnable setting for a specific serial port, use Device Manager.

Caution Image Caution

Not all FIFO buffers are reliable. If the application or the user notices that data is lost or not transmitted, set this value to 0.