Windows 10: The computer is glitching and giving me a lot of trouble

Until 2 days ago,the laptop was ok,working fine,but today,as I was playing some games,sometimes the character stopped moving,and no sound on the game,also,when I open the File Explorer,eventually it closes and 'refreshes' the desktop and 'unselect' the open apps,just like Google,Steam,Games,etc.
It also glitches a little the Wallpaper Engine.
So,I refreshed the Files Explorer on Task Manager,and it's the same thing,so,the File Explorer refreshes itself alone,without me doing anything.
I don't really know if someone has ever had the same problem,but it's giving me a really bad headache,since anything started being a really hard and annoying task.
If someone can help me,I would be grateful.

:)

 

Having trouble with port forwarding..

I am currently a bit occupied and can't focus 100%.

Give me some time to write a full check list for you. That manual helps a lot in doing all this.

I will return once I've written everything in a clear and step by step tutorial. I also have D2, so I will test it on my system, which also takes time.

 

Supported phones for Windows 10 Mobile Insider Preview


Your list confirms my phone is eligible, Lumia 521. The windows Insider App fails after ~ 15 seconds, restores data and gives me error 80073cf9. I trouble shot this and went thru all the steps mentioned on several websites including MS without any luck. Short of a hard reset, this is where I am now. Suggestions appreciated.

 

Why did the startup window get cleared?

I didn't missed any step, the list was gone and gone , even after using lot of programs the programs were not listed in that list.