UNMOUNTABLE BOOT VOLUME

Please help me, I have no idea where to go from here.

I ran a virus check on my computer and it suddenly came up with that irritating blue screen saying ‘unmountable boot volume’. I have tried countless number of tims to run it in safe mode and when that failed, I tried to reboot the system but there is absolutely nothing I can do to get that annoying blue screen to budge. All I know is it says unmountable boot volume. Any help would be much MUCH appreciated.

NB. ive heard about the reboot console but I dont nkow what it is or anything.
Please help!!