Unable to get usbport.sys above 250Hz when patching

[Marztabator]

Some of you may be aware that by editing a certain driver file (usbport.sys) it is possible to increase the USB polling speed from the default of 125Hz to 250, 500 or 1000Hz. I know this certainly worked well in the past.

But since moving onto XP SP3 since the past year or so, I keep finding that no matter how much editing and patching I do, the speed never goes above 250Hz. I don't know if it's a new hardcoded limit in the driver, or the mouse I'm using, or something else.

The current latest version of the driver is 5.1.2600.5551. Downgrading the file to 5.1.2600.5512 doesn't seem to make a difference.

So what else is it that could be the problem? All help appreciated, thanks!

[dencorso]

The current latest version of the driver is 5.1.2600.5551.

For what it's worth, no it's not. The latest usbport.sys is v. 5.1.2600.5778 from KB968764.