I just had some problems myself on my HP that is about 2 1/2 years old. I kept getting a message that said a Critical Process failed. I tried everything to fix from the menu they had and nothing worked.
I finally had to use my Lenovo mini computer and order a Windows Recovery thumb drive from Ebay. Well I got it and plugged it in and did a reinstall of Windows. I had everything backed up and then the external hard drive I had quit working and all my stuff was gone or so I thought.
I was looking at some Youtube videos on how to restore files after a reinstall and saw something to look at. I went to the computer files and lo and behold I found a file called windows.old and there were all my files. I got another external drive and downloaded them ASAP.
I then was trying to reinstall everything I had on the computer and noticed it wasn’t working right so I did another complete reinstall. That seemed to take care of my problems for now and I have been able to put back on all the programs I had running. Next time out I may look for another brand other than HP. Most of the time it usually a software problem and all you can do is a complete reinstall. Make sure you backup so you will have everything.
Most of the time after a reinstall when “everything is gone” it’s just that you are logged in as administrator and not the user whose stuff you are looking for. Look under C:\users and look at the stuff of all the users and you will probably find it. Log in as that user and the stuff shows up.