How to install a usb 2 driver in win xp sp3?

how to install a usb 2 driver in win xp sp3?

WHY do you have to... USB support is part of windows.

Smoothy is right, Windows XP SP3 supports it.
I suspect your motherboard does not support USB 2 and only 1.1
Also, some mainboards support USB 1.1 in the front slots and USB 2 at the back.

If I'm wrong, try updating the chipset and other drivers.

Find you motherboard's site and download latest drivers.
If you do not know what motherboard you have then download CPUZ, it will tell you.
Here is the link..
CPUID - System & hardware benchmark, monitoring, reporting (http://www.cpuid.com/softwares/cpu-z.html)

Hope this helps.
Grant