How could I reinstall the older S7 edge system version?

[AC Question]

Latest S7 Edge system grade has many errors. Cannot access to WIFI options, it shuts it down. Same situation with other features, but mostly with WIFI and; thus, unable to add/select what network to connect to

 

[underway99]

Most folks who have the Samsung update talk of how great it makes their phone. Before looking to reload Marshmallow, most if not all of your issues may be fixed by performing a factory data reset (FDR). This assumes that all was great with your phone before the OS upgrade. The FDR will slick the phone and make it like a brand new device straight from the box with the new OS7 loaded from the factory.

Here's how to do the FDR. How to factory reset an Android phone | Android Central


If you are dead set on reloading Marshmallow (OS6.01), here's how. I'd suggest that you read the entire thread (and the various linked threads) and be very familiar with the steps before you start the process. There is the possibility that this process will somehow fail, even if you do it right. So do your research to learn how to recover just in case it does.

http://forums.androidcentral.com/ambassador-guides-tips-how-s/499009-guide-samsung-how-flash-stock-rom-via-odin-new-interface.html

 

[B. Diddy]

Welcome to Android Central! It's also worth wiping the cache partition before resorting to the factory reset: https://support.t-mobile.com/docs/DOC-28028

 

[underway99]

I didn't even think of the clearing the cache first. That's normally number one on my list.

 

[Golfdriver97]

A cache clear is probably the best thing to do first. Then try the reset.

However, given the wifi acting up like that, it may be a bug in the ROM.