So I recently read about inceasing the USB Polling Rate on Windows 7 64bit and therefore plugged in my old ORIGINAL IntelliMouse (no China fakeshit) to give it a try.
Before going through the overclocking tutorial I first wanted to test the accuracy of my cursor (never had problems with it back in the days), opened up Paint and thats when I noticed the cursor doing strange movements on its own when I moved the mouse fast. There are no problems in the cursor's accuracy when I move the mouse slowly from one end to another (and yes, I deactivated mouse acceleration both in the Mouse options and in the registry files).
But maybe I'm absolutely unversed in this field and this issue is completely normal with a mouse this old on Win7, especially at 125Hz.
Afterwards, I went through the 125Hz to 500Hz tutorial (http://www.ngohq.com/news/15043-how-to-increa...a-7-a.html) step by step, but it just won't work for me - and I already repeated this tutorial a lot of times, making sure I don't do anything wrong, however it just stays at 125Hz (to make sure the mouse isn't broken, I tried it on 2 original Intelli mice already).

So maybe someone who also had a hard time changing his Polling Rate knows a fix to this issue?