You need to modify your Android’s settings to allow the installation of applications from other sources. Under “Settings,” select “Application Settings” and then enable “Unknown Sources.” Also under “Settings,” select “SD Card” and “Phone Storage,” and finally enable “Disable Use for USB Storage”
This last step is easy. Open Command Prompt and type the following: adb install <1>/<2>.apk
However, when you type the command, replace <1> with the path to your APK file and replace <2> with the name of the APK file.
You are done. Your application is now ready for your use.