My Envy 360 keeps on blocking spontaneously (losing work!)

[Guidoinperu]

Hello all and thanks in advance for helping. 
Since a few months my laptop every now and then just blocks. It generally happens when I leave for a moment, I come back and can't get the laptop to work again. I move the mouse, mousepad or use keyboard: nothing. Short clicks on the on/off button, no result. The light of the power button is always ON but it generally sounds silent. Nothing works, the only way to get out is to press the power button a long time, and then restart. And then restart all the programs I had open, of course. In the case of Excel, sometimes I lose the last things I had been doing, which is obviously rather annoying. 
I have been coping a long time with the problem because I have been busy traveling and all, just found no time to ask around for a solution. There have been quite a few Windows updates in between, but the problem persists.
It happens with or without an external screen connected. 
 It also happens sometimes when I am listing to internet radio but not using the laptop for anything else. 

It doesn't happen after a precise time of no use, and sometimes it happens a few times a day, or it doesn't happen for a few days, or only once a day. It's very irregular. 
I hope there are first some things we can try that don't require a complete reset of the system, it always takes so much time setting up the computer again, personal configuration, etc. This laptop has been giving me some trouble already 😉 

Thanks a lot. 

[WAWood]

@Guidoinperu 

From your description, I would guess your laptop is going into Hybrid Sleep and that is failing in the process -- forcing you to do a COLD START to regain control and, in the process, losing everything that was open at the time.

As a first step, go into Settings --> System --> Power & Sleep and ensure that Sleep is set to NEVER.

Then reboot the PC and see if that addresses the issue.

If not, repeat the steps but go into Additional Power Settings and see what is set there for power plans.  You want to disable anything that puts your PC to sleep.

Good Luck