1) The system is a lenovo ideacentre 310-15 asr , it's a pc not a laptop , he told me differently.Windows 10 Pro
2) He has the desktop since 2018 and no updates.
3) He tried this method>
Option A: Use Windows Installation Disk
Step 1. After booting computer from Windows installation disk, skip the first-screen language selection and choose Repair your computer.
Step 2. Select Troubleshoot and then Command Prompt.
Step 3. In command prompt type chkdsk c: /r and hit Enter. This assumes Windows is installed on your C: drive. If the drive letter for your system partition is different, type the real one. (You can run diskpart > list volume to check according to partition size.)
Step 4. Allow the process to complete and reboot.
3. When the Command Prompt appears, enter the following lines and press Enter after each line in order to run it:
bootrec.exe /rebuildbcd
bootrec.exe /fixmbr
bootrec.exe /fixboot
4. Restart your computer and check if the issue is resolved.
If the above steps didn't work, kindly check out the following thread:
I've encountered the SrtTrail.txt problem
D:\System32\logfiles\srt\srttrail.txt and 0xc000021a errors on boot Windows 10
Automatic Repair couldn't repair your PC
View: https://youtu.be/G0CgzUJ7tiE
View: https://youtu.be/IUKHp4Q_Fls
4) He doesn't know how to boot it
but this is how it looks
https://prnt.sc/ya04iw