Deleting anything inside of the
%temp% folder is a really bad idea IMO, and won't improve performance.
If you need to remove temporary files, your best bet is to run the Disk Cleanup tool that comes with Windows 10.
- Open file manager
- Click "This PC"
- Right-click drive "C:", then click the properties option
- Click on "Disk Cleanup"
- Select the options you would like, then click "OK"
This is the safest way of doing what you want to do. Be advised, like deleting %temp%, it won't actually improve performance in Minecraft.
Also for performance fixes, OptiFine is likely the best option besides getting a new computer. If you run the game in fullscreen, you can increase FPS by playing at a lower fullscreen resolution
Also:
Sadly, this won't make a difference
Props to the people running Linux :D Currently using Solus but run Fedora at home and work