I've come to these forums looking for help and hoping that a solution to my problem exists somewhere. This problem started happening when I plugged an iPod Shuffle into one of the USB ports (I had already installed iTunes). I got the "USB Device Not Recognized: One of the USB devices attached to this computer has malfunctioned, and Windows does not recognize it" pop-up bubble. I unplugged the iPod, thinking I just needed drivers, and was going to try again later. But when I tried to print something, my USB printer wasn't working anymore either. I tried plugging in a USB mouse and flash drive and got the same bubble as the iPod, and none of them worked. Now no USB devices work at all on my computer. I also noticed an "Unknown Device" listed in my Device Manager under Universal Serial Bus controllers (see below for more details). Plugging in any USB device yields the bubble and an additional 'Unknown Device' in the Device Manager.

Here are my specs:
Manufacturer: Gateway
Model: GM5084
Motherboard: Foxconn C51GU01 Socket 939 BTX Motherboard
Processor: AMD Athlon X2 4200+ 2.2GHz Socket 939 Processor
Memory: 2GB (4x512MB) DDR 400 (PC 3200) Dual channel SDRAM
Video Processor: nVidia GeForce 6100 Integrated Graphics
Audio Processor: Realtek AC'97 Integrated Audio
Hard Drive: Western Digital 320GB 7200RPM PATA Hard Disk Drive
Optical Drive: HLDS DL DVD+-R/RW CD-R/RW Drive
PSU: 300-watt PSU
Other: 9-in-1 Media Card Reader
Other: Hauppauge Amity II PCI TV Tuner Card
Other: Agere Systems Soft Modem 56K PCI Data/Fax Modem
OS: Windows XP MCE 2005 (all latest updates)

(Note: Sorry this post is so long, I thought it was important to detail the problem and everything I've done to try to fix it . )

I did contact Gateway support, and they were more clueless then me (as expected). Here are some more details of my problem:

Device Manager
-Universal Serial Bus controllers
--Standard PCI to USB Host Controller (<-No longer there, see 'UPDATE' below)
--Standard OpenHCD USB Host Controller
--Unknown Device
--USB Root Hub
--USB Root Hub

Before I go on, I would like to point out that there is nothing plugged into any of my USB ports, yet Unknown Device is always detected. All of the devices listed are 'working properly' according to the device manager. Also, both USB Root Hubs show 8 ports under Windows (total of 16). I'm assuming one is for USB 1.0/1.1 and the other is for 2.0, however, there are only 7 USB ports on my system, and the first USB Root Hub shows one of the 8 listed ports occupied by the 'Unknown Device'.

IRQ 5 NVIDIA nForce PCI System Management OK
IRQ 20 Standard OpenHCD USB Host Controller OK
IRQ 20 NVIDIA Network Bus Enumerator OK
IRQ 21 Standard PCI to USB Host Controller OK (<-No longer there, see 'UPDATE' below)
IRQ 21 Standard Dual Channel PCI IDE Controller OK

I only listed those because none of the other devices showed any sort of relation to the problem (everything was listed as status 'OK' though).

Things I have tried:
-Turning off Power Management features for the USB Hubs, both in device manager and registry: No change
-Removing Unknown/greyed-out devices (using DEVMGR_SHOW_DETAILS and DEVMGR_SHOW_NONPRESENT_DEVICES), rebooting: No change, Unknown Device reappears
-Removing any USB-related devices and programs, restacking USB Devices, rebooting: No change, Unknown Device reappears
-Manufacturer USB Drivers: Windows refused to accept them (The specified location does not contain information about your hardware.)
-Microsoft USB Drivers: No change, USB Root Hub (linked to Standard PCI to USB Host Controller) name changed to 'USB 2.0 Root Hub', but no difference otherwise
-Disabling Legacy USB Mouse/Keyboard Support in BIOS: No change
-Disabling USB 2.0 Support in BIOS BEFORE BIOS UPDATE: No change
-Turning off and unplugging computer (discharging PSU) with and without restacking devices: No change
-Disabling Standard PCI to USB Host Controller: No change
-Disabling Standard OpenHCD USB Host Controller: No USB period (device light flashes, but no bubble and no device detected), USB port still has power
-Disabling Standard PCI to USB Host Controller while a USB Device was plugged in, rebooting: No more 'Unknown Device' and no bubble, however, no power at all to USB ports
-Disabling Standard OpenHCD USB Host Controller while a USB Device was plugged in, rebooting: No USB period (device light flashes, but no bubble and no device detected), USB port still has power
-Updating BIOS: No change
-Disabling USB 2.0 Support in BIOS AFTER BIOS UPDATE: See 'UPDATE' below

Another quick note, using Everest Ultimate Trial, I noticed that only the 1.1 Root Hub was ever in use when I plugged something in and port 4 of 8 was filled with the 'Unknown Device', in addition to the device I plugged in (which was also listed as 'Unknown Device'), showing up in ports 1-3 and 5-8 based on the physical ports I plugged the device into. Disabling the Standard PCI to USB Host Controller with a USB mouse plugged in (requiring a reboot) left only the 1.1 Root Hub in Everest and no Unknown Devices; however, there was no power to any of the USB ports. Doing this with the Standard OpenHCD USB Host Controller removed the 1.1 Root Hub, leaving only the 8 empty 2.0 root hub listed ports. Plugged in devices received power but were not detected at all by the computer.

All of the devices I've tried work fine in other computers (I don't know about the iPod though, since I've returned it with the inability to put music on it). I was also told this could be a lacking-sufficient-power problem, but that doesn't explain why devices used to work before and there is not even enough power to allow a USB mouse or flash drive to work. Externally powered devices (such as a PSP) did not work with the USB either.

Things I haven't tried:
-Reformatting: I was told by numerous other people with the same problem that they tried it and it did not fix the problem.
-Chipset drivers: Could not find any matching my computer (did not want to install non-manufacturer drivers either, as the motherboard seems to be available through OEM only for Gateway).
-Motherboard replacement: Was told that it was the only thing that works (when hard drive is simultaneously reformatted), but I don't have the money and I'm having a hard time convince Gateway tech support that that's what they need to do.
-Removing and putting back the CMOS battery: Worked for one person, but my parents will not let me break the seal on the case cover to do this (voids Gateway warranty or whatever).

If anybody could help me with this problem, or give me any sort of suggestion, I'd be extremely grateful as weeks of searching and testing haven't shown any results and I need my USB working again badly. Thanks for the help.

UPDATE: On attempting to diagnose this problem, I disabled USB 2.0 support in the BIOS. Upon booting, it is normal to have the Standard PCI to USB Host Controller disappear from the device manager since this seems to be tied to the USB 2.0 Root Hub (according to Everest Ultimate Trial). I had already done this many times, and normally, renabling USB 1.1+2.0 support in the BIOS would cause the device to reappear. However, when I tried this after a BIOS update, the device disappeared but refused to appear even after enabling 2.0 support and scanning for hardware changes. I cannot make it appear anywhere in the device list or system information any more. The Unknown Device remains though.