Marks PC Solution

Well, you may experience this sort of problem with a newly purchased Android Phone or Tablet. For security reason, by default, installing apps from unknown sources are normally disabled in Android devices. But you can easy install those apps on your phone if you're confident about the security. Let's see how . . .  Before you proceed, you should know . . .  Android OS prefers installing apps from Google Play due to the security reasons. But sometimes you may need to install apps which are already stored on your phone storage. And that time your system may not allow you install such apps rather show the following message -  Install Blocked For security, your phone is set to block installation of apps obtained from unknown sources. Look at the above image. It also offers a Settings option. If you wanna change this settings, simply hit on the settings button and allow unknown source apps.  Allowing Unknown Source Apps You...