Please do try these troubleshooting steps that may help in solving the issue.
- Start by doing a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it back up.
- If it doesn't work try loading the laptop into Safe Mode, while the laptop is booting up repeatedly press on F8 until it load Advanced Boot Options and select Safe Mode.
- If it doesn't load Safe Mode your last option would be to run a Factory Reset to reinstall Windows.
- If it does load Safe Mode try running System Restore, restore it back to an earlier date or time before the problem even happened.