Computer fails to boot, no Windows disk, where to start

I have agreed to look at a friend of my sons computer, what I have been told is that it starts the boot process then crashes, then reboots starts the same loop again. The friend said they got it into recovery but it failed to recover. I cant give anything more exact than that as I have yet to see the PC yet. My understanding is that it was a Windows 7 PC which was upgraded on line to Windows10 . Apparently the kid does not have any OS disk (7 or 10) and no recovery disk of USB stick.

The first thing I want to do is boot from a linux boot disk to test the PC fundamentally works and to pull off as much of the friends data off the hard disk (assuming it is accessible) for safety (he uses the PC for college). My main concern if the issue seems to be file corruption of the necessary boot files which require either the original boot disk or a complete reinstall, what option do I have to reinstall an OS of some kind. I don't have any windows 7 discs I only have a windows 10 pro disk which I guess will not work.

I will of course try and revive the PC with the current OS installed (probably ask questions on here) but I just trying to prepare myself if the current install can not be saved.

You can create an install disk for that version of Windows using the Media Creation Tool. https://www.microsoft.com/en-gb/soft...load/windows10

A tutorial on making a bootable USB drive is here: Create Bootable USB Flash Drive to Install Windows 10

My personal preference would be to use the MCT to create an ISO and to make the USB drive using diskpart (command line utility). Make sure to format the drive as FAT32 rather than NTFS.

I don't know how helpful it will be. A repair install (upgrade in place) can fix many problems, but you can only launch that from within Windows. If the install USB drive successfully repairs the ability to boot, maybe you can proceed from that. Your plan to save the data before doing a lot of messing about is a good one, though.

Thanks guys, I will bear those suggestion in mind when I get the PC which is likely to be early next week

I now have the PC, it boots up with a stop screen with a large quick code on it which I have checked but the quick code does not offer anything useful and I have to turn the PC off to restart it again which will then go straight into automatic repair then changes to diagnosing your PC. Then it come up with a blue screen saying Choose an option Continue, Troubleshoot, Turn off PC. Troubleshoot takes me to another page with 5 option on it

System Restore
System Image Recovery
Startup Repair
Command Prompt
Startup Settings
Go Back to previous version

If I boot from the DVD I get as far as install, there is an option to Upgrade or Custom. Upgrade will allow me to keep the existing applications and setting but Custom will not. Unfortunately Upgrade fails.

Any suggestions how I can either repair the installed windows or how I can reinstall keeping all setting etc.?

OK after lots of googling and playing I have got it to boot to the login screen. It seems the issue was a failed update (it restarted the update at 35% when it rebooted), the error message was:

Bad-System-Info-Config

I followed the this youtube video

How to fix Windows 10 start-up problems - Blackscreen, Bootloop, Infinite Loading [HD 60FPS] - YouTube

Thanks for the info guys