My USB Port does not recognize my printer. I can plug anything else into the same port and it isn't a problem. I am also having trouble with the printer download. I had to down load the driver  and it isn't showing up on my add remove programs. The couple of things that is showing up there  is telling me I can't remove it, one SAYS something about a virtual library and the other says something about just-in-time debugging. The printer is an HP Officejet all-in-one. I am at my wits end on how to fix this problem.What OS r u using Win XP, Vista, Win7? also model of printer, besides the ALL n One it should state a model number.Windows XP PROFESSIONAL. The printer is a HP Officejet J4540 all in one. The numbers on the back are CN887881GJ CB780A [32]. It was given to me with no driver. Having serious problems with downloading the driver because I can't completely remove the programs from the previous printer that was on here.When I try to remove it out of add/remove program I get error msg's saying something about Just-In-Time debugging, and something about visual library. I just BOUGHT this computer second hand. I was able to download the driver on my OLD pc and the printer worked fine, but that pc crashed. Also mu USB port gives me an error msg. When the error COMES up I click on it and it brings up a list of USB ports and the one the printer is plugged into says unknown device. Lets start by doing a few simple troubleshooting steps:
1- check disk.
   G0>My Computer icon>double click>right click the C:\>tools>select check disk and select both options. Reboot, this will take about 30 to 45 mins.

2-Follow this link:
http://www.ccleaner.com/
This a program that will clean the Registry and remove programs. Read the instruction before using.

3- By now u should have a pretty clean hard drive (HDD). Uninstall all printer drivers. To play it safe after removing drivers reboot. Hey, this is Windows what can I say.

4-Download the latest and greatest drivers from the manufacture web site and install.

I will do one more check disk and Defrag the HDD.
Write back and lets us known the outcome.