System Reserved Drive at 100%

Recently, I have been away from my computer for some time. Before I logged on, I realized that something felt odd while doing so. The resolution of the log-on screen was jagged and much more lower than it should be.


But I'm not sure if the resolution is afflicted by the System Reserved Drive being at 100%.


Even if I try to defrag the drive I come to find that 1 file will always be optimized yet the percentage will keep still. 

 

 

Can anyone help me on this? Should I worry about it being at a stable 100%?And is there something that I can do to reduce it's percentage?