As you said you were downloading the Microsoft Office online maybe a virus has attacked your computer system leading to corruption of data. There are various manual methods available but they wont provide you a solution in case of severe corruption.For this you have to resort to various third party software's which are easy to install and have shown good results. If you are a bit confused regarding selection then I would first recommend you using Windows data Recovery by SysInfoTools . There are others also available like stellerinfo and kernel but since I have personally used SysInfo and it worked fantastically well I recommend you to first try it out and later look for other options

This problem could arise due to incompatibility issues or may be the HDMI wire is lose and not getting connected from either the laptop or the television side. First try connecting the HDMI to other tv so that you can get a good idea about the location of fault

Try rebooting and formatting your hard disk