How to Increase modem speed

Increase Modem Net Speed

Restart in MS-DOS mode, then edit the file system.ini in the Windows directory
(the command is edit c:\windows\system.ini).

Then create a new line in section [386Enh]:

COMxBuffer=1024 (where x is the number of your modem's communication port)
This will increase the buffer size for the modem, which will allow excess incoming/outgoing data to be stored in order to compensate for downturns in speed.