Welcome to FixYa
It seems that you are having problems booting to windows. There are a number of steps you can try to fix this issue.
1. boot to safe mode. Start tapping F8 right after the computer turns on. This would cause the system to boot to windows advanced boot menu. Once you see the advanced boot menu then just choose safe mode. If you managed to boot to safe mode then you can perform system restore from here. To run system restore just click on start, all programs, system tools, then click on system restore, once system restore has been launced choose a date when the computer was working fine
2. You can also try to boot to windows recovery environment. to do this keep tapping F8 right after the computer turns on. choose the option "repair my computer". The system would now boot to windows recovery environment. From here you can run startup repair and system restore
3. If none of the above steps work then you can use the One Key Recovery feature of a lenovo Y410. Please note that this would reset your computer to its factory image so this would cause you to LOSE DATA on the system. Before you use this feature make sure that you have a back up of all of you data. Note that the computer must be turned off.
Press the NOVO button on the computer. refer to the image for its location on your computer
Pressing this button while the computer is off would launch the one key recovery of lenovo. From here you can restore the system to its factory condition.
Hope this helps