Reset USB in XP without reboot

This is one of the odder issues I've come across to. I have Asus Eee 901 netbook running XP. The issue is with the USB ports: sometimes they appear to lose contact and this results into devices getting out of power for a moment. This isn't so big of an issue in itself, the devices can boot again just fine and most of the time I don't need to care about it, however my external HD just stops working at all. The device doesn't become available, it gets power but I guess Windows sends invalid command via USB and it doesn't get past initialization phase. This keeps happening no matter which port I change the device into so it must be a Windows, hardware or driver issue. The only way to fix it is to reboot Windows.

As of yet I haven't tried upgrading drivers, but I'm wondering if it is possible to reset USB as if the machine had rebooted without rebooting the computer?

there could be an underlying hardware issue. How many items do you have hooked to usb when this happens?

Two: a HSDPA/EDGE/GPRS mobile device and the external HD. The first mentioned is kind of a troublemaker, it is a first generation device that is hard to keep connected. However, the problem with the HD happens also when not using the mobile device.

i had a similar issue with a wireless device. It happened when it was hooked into a port set to "high" speed instead of "full" speed. The annoyance was any port on my computer could be used as both and each port showed up twice in device manager. The solution was to disable the "high" speed port. It slowed down the port speed to about 4megabit /second, but no more errors. I had the problem in both xp and vista but 7 seems to have fixed it.

I was having what sounds like the same problem. Resetting the item would not work and it would not work again until a reboot. Wireless adapter would even show available networks but not connect to them.

The required setting (for a usb hub) can be seen here, in this image.
It will either say full or hi speed. Try disabling the hub it shows the device hooked to and it will automatically connect to the other one.

Thanks, that solves the not-working issue. What I did was to go to the Device Manager and change the list to display devices by connection. That way I didn't have to go guessing which one was the USB 2.0 high speed connector (as all they said was Standard USB something), I could simply find the one that had a Mass Storage child device – and by luck it was the first one on the list.

So the issue is with USB 2.0, which starts to make some sense, but not enough: I wouldn't expect to have such problems for a machine bought in 2009! (Technology for it should be mature and all.) So, I'll have to go ahead and see if there are any different USB 2.0 drivers available or if there would be any other information available on this problem. I may need a faster HD connection someday.

it has to be a driver issue, surely. You could always check the manufacturer's website.