A simple trick i have been doing to "bypass" this is to actually just unplug the console 2-3 minutes, to turn it back on, and it should pass through safe mode with breeze. However, if it's truly damaged and gone, you should follow the official guide on Sony's Website https://www.playstation.com/en-us/support/hardware/ps4/system-software/#reinstall
There are 2 ways to go on about updating Windows to a newer version while keeping user data: RECOMMENDED FOR MULTIPLE PCS: You can install the Windows 10 ISO from Microsoft's website, flash it on a thumb drive, plug it in while the OS is running, then run setup.exe, it will guide you on how to keep everything. ( i suggested a thumb drive because i am assuming you are gonna do this on multiple PCs) RECOMMENDED FOR A SINGLE PC: You can just download the Windows 10 ISO, open it in explorer to mount it, then run setup.exe, should be business as usual. NOTE:You can't update PCs without having the OS running, booting the ISO is exclusively for new installs.
It seems like a bad/dead battery, have you tried to keep the laptop plugged in for a while? If so, does your OS show that your battery is 100% If the above is true, then you should look into replacing your battery, remember that dead batteries can do damage, so fix them asap!