So after update Windows has this nice feature to keep your old Windows just in case, because every time something is broken in the new update.
If you want to remove the old version of Windows or the folder Windows.old go to Disk Cleanup
Select drive C:
Click Clean up system files
Select C:\ again
Select all checkboxes and click OK.
In my case I already did this, but after update it we free you close to 30GB of space in C:\
If you liked this article you can try Iris, which makes monitors healthy for the eyes.
Your account will be closed and all data will be permanently deleted and cannot be recovered. Are you sure?