Problem:
I have a Lenovo Y510p that is currently stuck in the startup repair loop …
Resolution:
Try a Start Up Repair.
Hold down the shift key on your keyboard while clicking the Power button on the screen.
Continue to hold down the shift key while clicking Restart.
Continue to hold down the shift key until the Advanced Recovery Options menu appears.
Click Troubleshoot
Click Advanced options
Startup Repair
If the above fails try to repair Windows 10:
Here is the link to create Windows 10 ISO:
https://www.microsoft.com/en-us/software-download/windows10
Use installation or recovery media to get to startup settings:
1. Insert the USB drive or DVD and restart your PC. If you’re using recovery media, skip the next step
2. On the Install Windows page, select Repair your computer.