Good day sir, hi, usually its one or two ports that does not recorgnise a usb device, but if all ports does not recognise the usb device, check the CMOS setup. check this out;
- one or two ports does not recognise the usb device, this is a local fault, try to check the CMOS setup, this could also be the port itself is the faulty one having loose connection.
- all ports does not recognise the usb device, this is a system fault, check again the CMOS setup if the USB port is enabled, check the USB device itself also. to make sure use another pc to test the usb device.
A computer virus can also cause the usb port to malfunction, run an anti virus software, if possible you can reinstall the XP and test the USB port afterward.
If all else fails, you can buy a USB card and plug it on the expansion slot on your PC.