First you must create your own custom Coptic keyboard. To do this download and install Microsoft's Keyboard Layout Creator here. This program is easy to use. You just click on a key, a dialog box comes up, and you paste or type in the character you wish to use. In my previous post, I give screenshots of the character assignments I made. I also gave a list of all my letters. You can copy and paste those letters into the Keyboard Layout Creator. I assigned shift states for most of the unique Coptic characters.
In order to match J. Warren Wells' standard transliteration as shown in his pronunciation key in his lexicon, there are a couple of redundancies. The Ϣ and the Ϫ are on the "v" and "j" keys respectively. But they are also on the Shift+s and Shift+j keys.
The program is intuitive, but if you're having problems creating your keyboard, consult the Keyboard Layout Creator's documentation located in the Help menu.
Once you have created your keyboard, you much make it into a setup program that you run in Windows. In the Layout Creator, go into the Project menu, and click "Build DLL and Setup Package." Once this is done you must run the program that was created by double clicking on "setup" in the directory that was created. The keyboard should now be installed in Windows. However, you cannot use it until you add it as a keyboard.
To do this, click "Change keyboards or other input methods" in the Control Panel.
Click on "Change keyboards..."
Click on the "Add" button.
Windows does not support Coptic, so it is not listed. We must use another language with which to use the Coptic keyboard. I chose Corsican because it starts with "Co," just like Coptic.
Click on "Show More . . ." for a list of all the keyboards.
In the Microsoft Keyboard Layout Creator, I had named my keyboard "111" so that it would appear at the top of the list. Select whatever your keyboard is named and click Ok.
Your keyboard should appear in the dialog box under the language Corsican, as above. Now click Ok.
The keyboard should now be installed and ready to use. You can switch between keyboards by hitting Left Alt + Shift. I have English, Logos' Biblical Greek, and my personal Coptic keyboard installed. I can switch between the three on the fly by pressing Left Alt + Shift.
For more information on installing a keyboard layout, you can consult Logos' documentation provided in their PDF files for their various keyboards here. They also have an instruction video. You may also install their other keyboards such as Hebrew and Greek. They work good and are not beta releases like their Coptic keyboard.
Also note that if you create large Coptic files with your custom keyboard layout, and in the future a better, standardized Coptic keyboard is released, you can convert your files to the new keyboard by doing a simple Find and Replace for each Coptic character. Such a feature is provided in Microsoft's Word and Notepad. Because of this you don't have to worry about your hard work becoming obsolete.