How do you start Windows 10 in safe mode?

EDIT: The reason that the Windows 10 Boot manager doesn't work with f8, is because it has been disabled by Microsoft. to Re-enable it, follow these steps. (you will need a recovery DVD or partition available for your Windows 10 installation)

1. Power on your PC.
2. Use the appropriate key(s) to enter into the BIOS setup.
3. Configure your PC’s BIOS to use your recovery medium as the first boot device.
4. Reboot into the recovery medium
5. On the first displayed screen, click Next, and then click Repair your computer from the next box.
6. From the Choose an option window, go to Troubleshoot > Advanced options > Command Prompt.
7. In the opened command-line interface, type C: and press Enter.
8. Once the first commend executes successfully, type BCDEDIT /SET {DEFAULT} BOOTMENUPOLICY LEGACY command and press Enter.
9. In the command line-interface itself, this time type EXIT and press Enter.
10. Set your bios to boot from your Windows 10 installation again.
11. When your computer begins to restart, start pressing the F8 key repeatedly until you see the Advanced Boot Options menu.
12. Select the "Safe Mode" boot option

P.S. I think I found a solution to your problem here, apparently lots of people are having problems with "INTERNAL_POWER_ERROR" on windows 10.

Do the following:

1. When your PC is powered off, turn it on.
2. Once it gets past the BIOS screen, you should see the spinning circular indicator that tells you Windows 10 is booting up. At that point, press and hold down your PC's power button until it turns off.
3. Turn on your PC again.
4. Wait until Windows 10 starts booting up, and then for a second time, press and hold down your PC's power button until it turns off.
5. Turn on your PC for a third time.
6. Then Windows should load the Recovery Environment.
7. Select Troubleshooting, then Advanced Options, then Startup Settings.
8. Tell it to Restart.
9. After your PC restarts, you will see a list of options including various Safe Mode options.

I got the above steps from a Microsoft article, and they worked for me.

Edit: If you are not able to reach log-in screen then

1. You should boot from a recovery drive or an installation disk. If you don't have any of then you can create one with Media Creation Tool. You can create a recovery drive using this guide: How to create a USB recovery flash drive for Windows 10

2. On the Install Now screen choose Repair my computer at the left bottom.

3. Then you will see Choose an option screen, select Troubleshoot > Advanced options > Startup Settings > Restart.

4. After your PC restarts, you'll see a list of options. Select 4 or F4 to start your PC in Safe Mode. Or if you'll need to use the Internet, select 5 or F5 for Safe Mode with Networking.

This will work perfectly. There are many ways to Boot into Safe Mode in Windows 10.

One you are in Safe Mode work on this

Uninstall drivers

Right click on Start, and choose Devices. Then, uninstall Graphics and Network drivers - it can be one of them. Try to uninstall all possible drivers

Restart your PC