Windows won't boot

[Djfrashatch]

So my grandmother has a laptop that Shes never updated In the 4 years she's had it. She also hasn't turned it off in months. I suggested that she update and restart it because it was running slower than a sloth. We did that and it sped up to an acceptable level. It was working fine.  Afterward we left it off until the next morning. When turning it on it would only boot to the windows recovery page. I sat here for 4 hours running just about every scan that it'll let me, even one from command prompt, they either can't be completed or find nothing wrong. I've tried booting to a previous state and it won't let me. I've exhausted pretty much every option the recovery screen gave me short of going into bios or fixing the boot files on command prompt as I don't want the computer to break even more. The only other thing I can think of is a factory reset but we really want to avoid that. Any ideas that a non expert can do without messing things up further? PLEASE!!

Also, does deleting cyberlink programs cause any issues like this? It looked like a 3rd party app that neither of us ever heard of, so we uninstalled it because it was messing up the web cam. The webcam was fine after that but figuring that those were related we deleted the other 3 cyberlink programs. Nothing seemed important or gave me any warning, but is it possible that could've caused the issues we're seeing? 

[WAWood]

@Djfrashatch 

I understand the desire to NOT do a factory reset -- as it will completely remove everything from the drive.

As to the removal of the Cyberlink apps, that would have no effect on Windows 10.

There is something known as a Repair-Install in which you use Windows Media to reinstall just the OS, and that will repair the file system as well as any damaged system files.  But to do that, you have to do the following:

1) Figure out exactly what version and build of Windows you are running by  entering "winver" (without the quotes) in the search area and writing down what the window displays

2) Use that information and the instructions in this thread to download an ISO file from Microsoft:  https://h30434.www3.hp.com/t5/Notebooks-Knowledge-Base/Getting-older-builds-of-Windows-10-from-Micro...

3) Use RUFUS utility to create Windows boot media from that ISO file. You can get RUFUS from here:  https://rufus.ie/

4)Insert the Windows 10 USB stick into your PC (do NOT boot from it), find the folder containing the media, select the setup.exe file, right-click that and select Run as Administrator.  This will start an in-place Upgrade which could then take a couple of hours to complete.

5) If you are presented with a window asking for a product key, down near the bottom is a entry you can click to skip that. Do NOT enter a product key, as it will reuse your existing key and when you finish and get back online, Windows will automatically activate.