Reboot your computer into safe mode. If you need help doing that, read below; otherwise skip to the next step:
- As it's starting up, you should notice a splash screen with machine information, or possibly a logo (such as a Dell logo).
- When that splash screen vanishes, immediately start tapping the F8 key on your keyboard. Twice per second or so is plenty. Some machines get rather cranky if you start tapping F8 during the splash screen, and some don't. Yours may vary.
- After a few moments, the machine should show you a list of possible boot options. If it doesn't, wait for the machine to boot, then restart it and try again.
- One of the possible boot options is "Safe Mode". Please select that option by using the up/down arrow keys on your keyboard, and press Enter when it's highlighted.
- There are multiple Safe Mode entries; please select "Safe Mode", not the others.