Try staring the laptop in 'safe mode' and selecting the option as outlined below.
Here is the procedure:
Restart the computer
Wait for the computer to complete the POST process (Acer appearing on your screen)
Quickly press the F8 key repeatedly until you see a list of boot options available. (Between the Acer screen and the Windows starting screen. If you start too early the laptop will beep, just release the F8 key for a few seconds and start tapping it again. If you are to late and the starting Windows screen appears shutdown the laptop by holding the power button until it shuts down and then start again. It is all the the timing you only have a small window of opportunity to access the advanced startup options menu. That is why you should tap F8 very quickly
Choose Last Known Good Configuration (your most recent settings that worked)
Wait for your computer to boot into this mode all the way to the Windows desktop.
Once it is there, wait for the HDD activity to settle down a bit, (the HDD light should stop being on continuously) and then shutdown the laptop in the normal manner from the desktop.
Once the laptop has shutdown completely restart the laptop and see if it starts normally.