Some of these programs modify the system registry to permanently change the key bindings, while others take a different (read temporary) approach wherein they do not modify the registry.
Windows is the easiest to key remap of the lot, and there are many different programs that let you do so with ease. We'll go over these programs for all three major computer operating systems one-by-one. Now, depending on your computer's operating system, there are various key mapping programs, each promising to provide a slightly different set of features while retaining the core functionality. It involves assigning the value of one key to another, thereby enabling the corresponding character to appear when pressing the other. Remapping a key is a fail-safe solution to fixing a broken keyboard. An alternative solution at such times is to remap the broken key to another key on your keyboard. However, there are instances when this doesn't work. While there are several ways to fix a broken keyboard, the simplest (and beginner-friendly) method is to blow away the dust or debris entrenched in the keyboard activity. In general, regardless of whether you use a laptop or an external keyboard, it's plausible that it could run into such keyboard problems over time.
If your keyboard has a broken or missing key, working on it can be challenging.