I strongly suggest that those with a sincere desire to FIX their AutoCAD spend an hour or two scrolling through the SYSVDLG.
I favor clicking with the cursor arrow, as it will briefly open each variable, and will likely teach you a lot, on the fly.
One size does not fit all, any more than a DEFAULT variable setting delivers optimal performance for everybody.
If that were the case, there wouldn't be any other options, nor need for them.
Next time you find yourself bored, with nothing on your plate, waiting for the next "Hot Potato", which was promised for yesterday to materialize
on your desktop invest a little of that inevitable downtime making your life and software work better for you.
Work SMARTER not harder, the time and frustration you save will be your own.
It is a good idea to take notes of those variable settings which you have changed, in case you later discover that maybe you made a mistake.
Better yet, use the SAVE ALL button at the bottom of the dialog to make sure you have saved a .svf (system variable file) which will
contain all of the current settings on your machine, and put it someplace safe where you can find it, when you need it later.
If you are running pure Autocad Default settings, and want to restore them, choose the READ button at the bottom of the dialog
to restore ALL default variable settings.
Once you have started customizing and personalizing your variable settings that .svf file becomes really important.
It enables you to share with your team, or apply your settings onto another machine.
Should you be borrowing/hijacking a friend or coworker's station, be sure to do a SAVE ALL of their settings before overwriting them with your own,
so that you can restore them when you are through on their desktop.