When you restart your computer, COM port setting revert to the default value?

You can change them in Device Manager or at the a command prompt, but they are not retains after a restart?

If you Open a CMD prompt and type MODE COM1:, you receive a display similar to:

<b>Status for device COM1:
    Baud:            1200
    Parity:          None
    Data Bits:       7
    Stop Bits:       1
    Timeout:         OFF
    XON/XOFF:        OFF
    CTS handshaking: OFF
    DSR handshaking: OFF
    DSR sensitivity: OFF
    DTR circuit:     ON
    RTS circuit:     ON</b>
In Microsoft Windows 2000, COM port settings for command functions are maintained only for the active Windows session. Custom settings are discarded at shutdown.

To workaround this feature, create a Minimized shortcut in your startup folder. If you wanted COM1 to be
Baud rate=9600; Parity=None; Data Bits=8; Stop Bits=1
set the shortcut target to:

C:\winnt\system32\mode.com com1: 9600,n,8,1