bought windows (home I think) around a year ago from a website for cheap and when I got home from school today the watermark
How cheap is ‘cheap’. Sounds like you used some random key selling site and your key got blacklist/revoked. Sucks to be you. R8 applies.
Get your keys from legitimate sources
You dont, it’ll use as much as needed. And if you have a dedicated GPU, VRAM on the GPU takes priority over using (additional) system ram