Project XiCam Back on Track

Well, it was quite a debacle, but I finally have the HP back in working condition.  The USB issue turned out to be a hardware-level problem and required a full BIOS update to fix.  Here's a summary of the problem I encountered and what it took to fix it:

• Plugged my phone into one of the USB ports at which point the computer stopped responding to the mouse.  I thought the error might have come from a conflict after installing libusb-1.0-0 with its corresponding dev package.
• Ran apt-get remove the packages I had just installed and it removed a whole bunch of critical packages that were reassigned as dependencies.  After install, it realized it needed to re-update them all so the whole thing was a mess.
• Rebooted computer and found the OS in an infinite loop on the logon screen.  When I deliberately put in a wrong password, it indicated the bad password with a red "invalid password" message.  When I entered the correct one, the screen would flash an error for 1/2-second an return to the logon screen.  I tried to find a solution on-line.  The most common cause of the problem was an .Xauthority file getting set to the wrong permissions.  This was not the problem, though.
• Found an old Ubuntu install disk and started the computer in live mode.  I had access to all the old directories and tried fixing the problem from there without any luck.  Eventually I resigned myself to reinstalling the OS so I backed everything up on a SD card (the USB ports were still not responding, which I think should have been a hint that an OS reinstall wouldn't help).
• Reinstalled Ubuntu 12.04 but USB ports still didn't work.  Checked /var/log/syslog and there were repeated error messages.  The messages would change when I connected the mouse, but the system never responded to the mouse.  Did some more checking of the interwebs but none of the fixes I found worked in my case.  Checked HP support site and started researching USB host drivers, which apparently, for my computer, are owned by Microsoft, so I decided to restore the HP to factory default.
• Reinstalled Windows Vista from the recovery disks.  This still didn't solve the problem.
• As a last resort, I downloaded the BIOS update.  This required Windows to run the installer.  This finally worked!

Lessons learned:

• Take extra care installing USB packages in Ubuntu.  If there's a conflict, you won't be able to remove them without affecting a lot of other critical software.
• The USB drivers on HP notebooks are integrated as part of the motherboard chipset.  If something goes wrong with it, then you need to flash the BIOS.  In the case of this computer, this requires running from Windows (I've heard many complaints about Vista, but to be honest it's always worked well for me; I'm also a fan of Windows 7).