Well the Hertz of the mouse sometimes can be increased by uncapping the speed of the usb port the mouse is connected to which is how this USBSMR program works. I will attach it. To use it, you must restart your computer into safe mode and run the program. I think it is because when it is in safemode the file that it needs to mod is not in use whereas in normal XP mode it is in use. I know this works with XP, As to vista i highly doubt it although i havent tried it. The program will show you your current hertz, on most older mouses and some newer, the hertz is capped at 125hz which is a slow down if your mouse is capable of alot more.
READ HERE FOR A COMPLETE TOUR OF THIS SUBJECT
ESR - Article
Anyway the usb mouserate switcher is in rar, extract it and the use of the program is very simple. I recommend that nobody try to use it in normal xp mode (I think it also works in WIN2k).
I have the IntelliMouse explorer 3.0 and 4.0. Regen told me that the 4.0 is HARDWARE LOCKED at 125hz so uncapping the usb port that the mouse is connected to will not affect the speed AT ALL. And in the esreality article, if you look at the Intelli Explorer 4.0 page, it will show that there was no change in Response time or malfunction speed. But the 3.0 is a whole different story. Its best for people serious about changing their mouse, or people looking for something that will help their mouse performance to read the link i provided because its very helpful. My current mouse hertz is at 1000hz but from that article the guy tested and concluded that this mouse and certain others would run best at 500hz. Hope this helps