Pc gone really slow!

I don't know if this is the right place to post this, if not please re-direct me. So I was using Movie maker a couple of days ago to make a 57 second video for something. When It was saving it for a video file, it was using most of my ram and was going extremely slow. So I was stupid and decided to hold the power button to turn it off. When I turned it back on however it decided to go VERY slow for a new pc. I was thinking it must just be loading, but this slowness continued for half an hour. So when I looked in Task Manager, I saw that 90% - 96 % (around 3.5Gb) of my 3.71gb of my usable ram was being used. When I checked however none of the processes added up to that number. The most was Google Chrome which used 130 K (there abouts) of memory. I thought that was odd and I've looked up MANY solutions to high ram usage problems. I've looked in Resource manager and it still doesn't show whats been used. I saw a post suggesting to download RAMMap. I did this and when I looked, it showed that 2.57gb of Ram was being used in something called 'Driver Locked' (Pics below). Can anyone help with this? Pics:






Thank you