Starting a recovery via the recovery partition usually means that you have to press one of the “F” keys (such as F1-F12) the moment after you hit the power button. These should be:
- Acer – Alt + F10
- Asus – F9
- Dell/Alienware – F8
- HP – F11
- Lenovo – F11
- MSI – F3
- Samsung – F4
- Sony – F10
- Toshiba – 0 (not numpad) while turning on, release key when Toshiba logo appears