Microsoft OnLine Service.To prevent maintenance and upgrade problems, carefully choose the file and module names for your driver, and the filename and ID number for your virtual device.
If you create your own device driver, even if it is a slight modification of a sample driver, you must provide a unique filename for the driver. The module name should be as given in the following list.
| Driver | Module name |
| Communications | COMM. |
| Display | DISPLAY. |
| Grabber (standard mode) | No module name required. |
| Grabber (386 enhanced mode) | GRABBER. |
| Installable Drivers | Must be unique. |
| Keyboard | KEYBOARD. |
| Logo code | No module name required. |
| Logo data | No module name required. |
| Mouse | MOUSE. |
| Network | Must be unique. |
| Printer | Must be unique. |
| Sound | SOUND. |
If your virtual devices replace standard virtual devices included with Windows 3.1, use the same virtual device ID numbers as the devices being replaced. If your virtual device is a supplement, rather than a replacement, you may need to obtain a virtual device ID number from Microsoft DDK Product Support Services (PSS). Virtual device ID numbers are assigned by the DDK PSS. There are a number of ways to request virtual device IDs:
Microsoft OnLine Service.
Microsoft SDK Forum on CompuServe.
Electronic mail to vxdid@microsoft.com through MCI MAIL, CompuServe, or any service that has InterNet access.
If sending electronic mail, you may need a prefix for a given service, for example, CompuServe mail is: >INTERNET:vxdid@microsoft.com.
In all cases, if you create your own virtual device, even if it is a slight modification of a sample virtual device, you must give the virtual device a unique filename.
For more information about filenames for device drivers and virtual devices, see Appendix B, “Windows 3.1 Driver Filename Policy.”