I think computers can get slow when they are downloading shit in the background. Windows Updates have messed up performance on my work laptop many times.

I think it might just be a coincidence. I believe GPU drivers are updated fairly regular, so it’s most likely that everytime you had a slowdown on your computer for whatever reason, there happened to be an update ready. Corrolation =/= causation.

Others have stated that the restarting after driver install most likely “fixed” your pc everytime.