1. Locate usbport.sys in %SystemRoot%\System32\Drivers
2. Take a backup of the file, save it like usbport.BAK for instance.
3. Hexedit the file, locate this sequence of hex values: "3C 08 73 09 C6 86 0A 01", look in FAQ
if you can't find it.
(You can google for one, a lot of free hexeditors on the net. I used Hex Workshop 4.0)
4. It's found at different offsets depending on what usbport.sys version you got. non-SP/SP1/SP2
5. Replace that string with this one: "B0 04 73 09 52 8A 0A 01"
6. Save&reboot
7. Go into safemode (this is to avoid WFP), replace the patched usbport.sys in both
%SystemRoot%\System32\Drivers AND %SystemRoot%\System32\dllcache (hidden folder)
8. Reboot, and it should all work fine.
9. Back in WinXP, check samplerate, and you SHOULD notice the change. For the ones with total
blindness for such things; you will notice that sensitivity feels LOWER.
Other things: Better responsetime/less jitter/mouselag/whine from you.



If you do find "3C 08 73 09 C6 86 02 01" instead, then your patches will also have to change for 250hz and 500hz. The correct ones will then be: "B0 04 73 09 52 8A 02 01" for 250hz, and "B0 02 73 09 52 8C 02 01" for 500hz.