I recently found out that i had a number of updates totaling to slightly over 900MB since i turned off all windows updates (Not Recommended) last year December . After completing downloading, it installed them and i was prompted to restart which i did as usual and after signing in, i got that flashing Screen. I got a solution.Switch off your PC by unplugging the power supply cable and removing the battery. Re install back the battery. Press the power button and immediately press the f5 button repeatedly till you get a 'Please Wait' Screen. A recovery screen appears, select 'See advanced repair options'. Choose an option , select Troubleshoot. Troubleshoot, choose advanced option. Under 'Advanced option', choose 'System Restore'. Proceed as prompted. Check out the video here This is how i did it and i solved the problem on my PC. I hope this will help someone out there.