Method 3: Using an Installation Medium
This is one of the easiest methods to reach the Windows 10 RE Environment from where you can boot Windows into safe mode. You can use a Windows 10 Installation Disc or USB Thumb Drive for it, if you do not have this then you can download Windows 10 Enterprise Evaluation Version from technet and burn that to a disc, or use a Windows 8 Installation Medium
1. Boot your computer from the USB Stick or Installation Disc.
2. Choose your keyboard, input and Language settings and click on Next.
3. In the bottom corner of the screen click on Repair Your Computer.
4. You will now see the “Choose an Option” screen, click on Troubleshoot
6. Then click on Startup Settings, you will be asked to Restart your system, click on the restart button.
7. Now press the 6 or F6 key, or any other key instructed by Windows to enable Safe Mode. Windows will now automatically boot into Safe Mode.
Method 4: Using the F5 key
This wont work on newer systems, since the system using Fast boost and almost immediately skips the part of the boot process that intercepts the F5 user input. However some systems still do accept the keystroke. Before Windows starts loading (black screen) repeatedly click on the F5 Key. You should then get the option to boot into Safe Mode
Like I said, this wont work for most modern / newer systems.
Method 5: Read your Manual
Most system manufactures add a boot options menu or recovery menu button to the start-up process, for example some Asus computers have the F9 key which brings you into the Windows Recovery Environment. However the key is not the same for all brands. I recommend you read your manual to see which key you should use.
Method 6: Force Boot Failure
This is my least favorite way of invoking safe mode. In order to make Windows believe it cannot boot you can forcefully shutdown your system during the boot process, when Windows starts loading, hold the Power button till the device turns off, repeat this step till Automatic Troubleshooting appears, wait for it to finish. It will say it could not find any issue, click on Advanced options and you should be in Windows RE.
I HIGHLY advice you not to use this method!