To change the mouse pointer speed in Windows 10 use the Mouse Properties option window! (... See Image 1). The fastest way to open it, is via the Windows 10 Control Panel and a click on the Mouse icon! Or using the keyboard shortcut Windows + R and the command control.exe /name Microsoft.Mouse.
Jiffy is an informal term for any unspecified short period of time, as in I will be back in a jiffy. From this it has acquired a number of more precise applications for short, very short, or extremely short periods of time.
The origin of the term jiffy is unknown. It is thought to have first been used in England during the 1700s, and referred to a brief but indeterminate time. But in some contexts, it is used as a put-off: the expression in a jiffy can mean maybe now, maybe never..