There is few steps must follow to configure DOS2USB depending on your operating systems.
     If you are using Windows95 or Windows98

• After you install DOS2USB then you need to change some settings in your printer driver.  

• Click on Start Menu, Click on Settings, Click on Printers.  

• If you have installed a printer and its driver on the LPT port then please follow these instructions to disable Windows default port capturing.

• Right Click on the printer and select Properties