Hello BRIAN, welcome to the Microsoft community, I'll be happy to help you today;
I understand that you have tweaked Windows for better performance;
Your files didn't have thumbnails because you wish you had turned off the "Show thumbnails instead of icons" option;
There are other ways to make your laptop faster;
Do a clean boot;
Press together the keys: Ctrl + Shift + ESc to access the Task Manager;
Click Start and disable all programs that start with the system;
Do a disk cleanup;
Press Windows key + R and type: cleanmgr press Enter;
Click on Clean system files and wait for the files to load;
Select all files and click OK to delete them;
Restart your PC and check if your PC performance has improved;
Hope this helps, see you soon!