If you computer is still booting normally, then when logged into Desktop of Windows 10:
- Press Windows key + R
- In the run dialog type msconfig and click OK or press Enter key
- Now select the Boot tab
- Check the box next to Safe boot
- (If you want Safe mode with Networking, also check the box next to Network)
- Click Apply/OK and restart computer
- On restart sign-in to Safe mode desktop
When in Safe mode repeat steps above but remove check next to Safe boot and click Apply/OK so you can restart computer and boot back to normal Desktop.
Alternately, you can press and hold down your SHIFT key while at the same time right-clicking on Start and selecting Shut down or sign out > Restart
When the computer restarts you will be greeted by the Recovery Screen as illustrated further down this posting.
You'd then click on Troubleshoot > Advanced Options > Startup Repair > Next button to restart computer where you can choose either option 4 for Safe mode or option 5 for Safe mode with Networking or option 6 for Safe mode with command prompt
If your computer will not start then insert either a bootable DVD or USB Flash device, containing the Windows 10 media. You may need to alter your BIOS settings to boot from this media.
When it boots from the DVD or USB Flash drive, you'll eventually get to a screen like so:
Click the
Next button to be taken to the following screen:
Click the
hyperlinked Repair your computer to be taken to the following screen:
Click on
Troubleshoot to be taken to the following screen:
Click on
Advanced options to be taken to the following screen:
Click on
Startup Settings to be taken to following screen:
Click on
Restart
When the computer restarts you will see this screen where you can select option 4, for Safe mode, or option 5 for Safe mode with networking, or option 6 for Safe mode with command prompt: