How to disable your capacitive button and add the navigation bar(software keys) on android

Disclaimer: You need root to do this, this has been tested on android 4 up to android 4.4, but should work with newer android versions.

If you are like me and the capacitive buttons of your phone started acting funny or you just want to test how it's using the navigation bar, just follow these simple steps:

• Download a file explorer that lets you access the root of your system (Root Explorer, for example), open it, go to your root and then to your system folder.
• In your system folder there's a file called build.prop, open it and add the following line to it: qemu.hw.mainkeys=0 that can be added anywhere in the file, it just has to be in its own line. After adding that line, save the file.
• Go to the usr folder inside system (where you are right now), and then to the keylayout folder.
• In here you'll find a Generic.kl file, this is a text file, but it might not be recognized as such by your programs, if this is the case, you can change the extension from .tl to .txt.
• Look for the following lines:
• • key 139 MENU VIRTUAL
• • key 158 BACK VIRTUAL
• • key 172 HOME VIRTUAL
• • key 580 APP_SWITCH VIRTUAL
• And uncomment them by adding a # at the start of the line, like this: #key 580 APP_SWITCH VIRTUAL. Most phones only have 3 capacitive buttons, some have a button for menu whereas others have an app switch button, so uncomment the ones that are relevant for you.
• Save the file and if you changed the extension from .tl to .txt remember to change it back to .txt.

And that's all, after you reboot your phone, your capacitive buttons will be disabled and you'll have onscreen buttons. It's likely your capacitive buttons will still light up, however, there's no generic solution to turn them off. Some phones have the option on Configuration > Display, but others will lack the option, so you need to look in your favorite search engine for your phone.