First of all, remove all removable devices (USBs, external hard drives), CDs, and DVDs from your computer
If you use Windows versions other than Windows 8(.1)/10: Turn on / Restart your computer and press F8 repeatedly, before the Windows logo appears
*If you use Windows 8(.1)/10, press and hold the SHIFT key and F8 key, or press the SHIFT key, restart your computer, and hold the key while your computer is restarting.
Once the Advanced Boot Options screen appears, use the arrow keys to highlight Safe Mode with Networking, and then press Enter
In Safe Mode, Windows might look different because Safe Mode uses a low graphics mode for the display. Also, the words Safe Mode display in the four corners of the screen.
Restart the computer to leave the safe mode.
Note: If your computer has a single operating system installed, press and hold the F8 key as your computer restarts. You need to press F8 before the Windows logo appears. If the Windows logo appears, you'll need to try again by waiting until the Windows logon prompt appears, and then shutting down and restarting your computer.
If your computer has more than one operating system, use the arrow keys to highlight the operating system you want to start in safe mode, press Enter, and then immediately press F8.
Also, some laptops require the Fn + F8 combination in order to let you in the safe mode.