[Wingy]

This should work in PowerShell on Windows or on other systems with a normal shell as long as your downloads folder is called Downloads and you don’t have a folder called old next to Downloads:

mv Downloads old && mkdir Downloads && mv old Downloads

This is assuming there aren’t any special permissions/attributes on Downloads

[bombcar]

Some of them seem to have weird things where renaming a directory keeps it still the "downloads" directory - I prefer moving the contents of downloads instead.