Need help on USB connection

Hi there,
I'm having bad problems with my USB ports. I am using Win XP Pro on a Pentium 4. Normally my USB ports work fine, though sometimes it doesn't detect my hardware, but when i restart, it detects again.
But this time round, when i connect in my Canon digital camera, it doesn't detect it, which is weird since all along it could detect. I restarted my computer several times, but still it doesn't detect it. Then i switch different USB ports, and none detected it. Then i connect in my USB soundcard to test, and as well, the ports didn't detect that as well.
I checked the drivers on device manager, and it shows it's working properly. I checked and found the drivers are USB 2.0.
It seems everything is fine, but the USB ports just don't detect anything now. Whatz wrong with my computer???

Welcome to WinDrivers:

start here and report back - thanks -

http://www.usbman.com/WinME%20USB%20Guide.htm

edit: and here:

http://www.michaelstevenstech.com/bios_manufacturer.htm

It may be that if you have been having issues with detection in the past, the ports themselves may have decided to give up permanently.

Can you beg or borrow a usb mouse and see if that gets recognised?

Do you know how to get into the bios? If so try disabling rebooting then re-enabling the usb in bios.

Do you have WinXP service pack2 installed on your computer?

EDIT: Already covered by CCT's link.

Better to remain...........................than to remove all doubt.

I did disable USB legacy support, but nothing happen. It still doesn't detect anything....

How to tell whether my pc is with SP2??? I did a windows update with SP2, but i don't know how to tell if it's already installed with it??

Check Control panel, Add/Remove programs - if SP2 shows it is installed.

Or right click my computer > properties - the service pack level shows up on the general tab.

Disabling usb legacy support would not help
Did you manage to borrow a usb mouse?
Did you try getting into bios and disabling all usb?

Did you check on your Mother Board Disk install USB2.0 after SP2 is installed