[acme266]

My mobile have a lag so I want to reinstall my android, mabye it will fix a lag..

[srkmagnus]

My mobile have a lag so I want to reinstall my android, mabye it will fix a lag..

Welcome to the forums!

Rather than re-installing the software, try clearing the cache partition first then a factory reset. If that doesn't work, then try installing the factory firmware.

To get into recovery to clear cache: power off. Hold volume down+home+power button until recovery loads. Use volume down to highlight clear cache partition and power to accept. Let us know if that works.

[acme266]

Welcome to the forums!

Rather than re-installing the software, try clearing the cache partition first then a factory reset. If that doesn't work, then try installing the factory firmware.

To get into recovery to clear cache: power off. Hold volume down+home+power button until recovery loads. Use volume down to highlight clear cache partition and power to accept. Let us know if that works.

First way does not work. I getting word "warning" when try first way. Second way i don't understand. How to install the factory firmware?

[srkmagnus]

First way does not work. I getting word "warning" when try first way. Second way i don't understand. How to install the factory firmware?

You'll have to find a copy of the factory firmware and install it with Odin. These items are not publicly released by Samsung and you'll have to find them online. I would advise against that since it doesn't sound like it's necessary for you scenario.