How to reverse the scroll direction in Windows8?
Solution 1:
I had to change this setting as soon as I started to play with Windows 8.1.
Just follow the directions laid out in this tutorial and you'll be all set.
http://www.eightforums.com/tutorials/38359-precision-touchpad-scroll-direction-set-windows-8-1-a.html
Solution 2:
Your Logitech device has special software utility called SetPoint which allows various adjustments of keyboard and trackpad on your device.
You can download it from K400r support page.
Since SetPoint 6.51.8 you can enable "Natural scrolling" which reverses scrolling direction.
Open SetPoint, go to Scrolling tab, click on Scrolling options and check the first option.