With the release of OS X Lion in 2011 Apple introduced natural scrolling to the PC. By default Linux and Windows still use reverse scrolling, but this can be, er, reversed.

X

Some distros have a parameter that can be set in the GUI setups. If not:

Most Linux distros use X, aka the X Window System or X11.
# get the {idnum}
xinput list
# if 4 and 5 are reversed, scrolling is reversed
xinput get-button-map {idnum}
# give as arg the desired code e.g. 1 2 3 4 5 6 7
xinput set-button-map {idnum} {order}

Windows 7

1. Get mouse ID: Control Panel > Hardware > Properties > Details > Hardware IDs > VID
2. Change the registry:
   1. Run regedit.exe
   2. Open Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\HID
   3. Find an entry for the mouse ID
   4. Set all DeviceParameters key FlipFlopWheel to 1
3. Unplug and replug mouse.