All USB ports not working Windows XP

My wife after down loading pictures used the "Safely remove hardware" on all my drives.  Now none of my USB ports work.  I've uninstalled them and restarted the computer, I've turn on or enabled everything to do with plug and play devices.  Under device manager all the USB ports are there and they are all working properly however nothing that I plug into them will work.

Thanks but it didn't work.  I think the problem is bigger than that.  All my USB ports have power and will provide power to the device I plug in.  However the device will not show up under my computer.  All the drivers are there and updated, all plug and play items are turned on and active, under device manager it says all usb ports are working properly.  I've uninstalled them and reinstalled them several time with no joy. 

Please help

I have had the exact same problem with my usb ports. When it happened to my computer we had recently had a virus removed from the computer through the Microsoft Security Essentials program. A USB mouse was plugged in as well as a 2GB flash drive that was nearly full. I had an ipod USB connector plugged into a port but the ipod was not attached at the time. But as soon as I plugged in the ipod all of the USB ports refused to work. As handiman said above, the ports provide power but will not detect devices. For example, I can plug in an ipod and it will charge but the computer will not detect the ipod, and in itunes I have set it up so that it will open whenever the ipod is plugged in.

I am having a similar issue.  All USB ports are disfunctional with the exception of the two on my monitor, of which the monitor is plugged into a port on the back of my machine.  It's a Dell XPS 400 and it has NO OTHER mechanism for running a keyboard or mouse except for USB -- hence why uninstalling/reinstalling isn't really a viable option because once things are uninstalled, I have no keyboard or mouse.

Updated BIOS, chipset drivers, powered off things, even jumpered the CMOS -- nada.  And I know it's Windows XP because even with the ports working on my monitor, they will on occasion suddenly stop working...no power to the devices.

I know the ports are good as they work via the BIOS.  And here is the REALLY weird part -- if I plug in a flash drive in a port and reboot the machine, when it boots back up, it sees the flash drive.  However, if I remove it and then plug it back in -- nope...not recognized.

People all over are having this issue, but nobody is coming up with a solution.  It seems sad to see people tossing their computers when it's got to be a Windows issue...there is power going to these ports, but the OS does not recognize them, even though the device manager says everything is okee dokee.

HELP

this helped... thank you.

Did what 'Jodido47' said, work?

 I would have suggested to go into MB bios and make sure that USB support was "enabled"

 Or reload USB drivers from the MB driver CD.

  But I was just wondering if his trick worked.