What operating system and revision is on the computers that do not work? Was the specific wording of the error what you said?
"one of the usb installed in this computer has malfunctioned and therefore is not recognized"
Because it really doe not make sense. Could it be "one of the USB devices installed...
A PC computer has to meet the following requirements:
Windows system requirements
PC with USB 2.0 port
Windows 7; Windows Vista; or Windows XP Home or Professional with Service Pack 3 or later
iTunes 9.1 or later (free download from www.itunes.com/download)
iTunes Store account
I think now the minimum requirement for itunes is now 10.X because of iOS 4.2.1.
So you plug in your iPad into your PC and this error shows up on the PC? That shouldn't occur, iPads should be recognized on the PCs, you don't need to purchase a Mac.
A quick google search shows that a lot of PC users have run into this USB issue though unfortunately:
Here is one link:
I won't be able to help you troubleshoot since I don't know much about PCs, but you should at least post what type of PC/OS you have so that others in the forum might be able to chime in. Also you might want to post on other PC related forums too, you never know who might respond.
I had the same issue. All worked well until I updated iTunes to 10.1. The next time I plugged in my iPod and IPad to the USB port, I got the same error message. Tried different USB ports, no go. Plugged other devices into the same USB ports and they worked fine, leading me to believe it was a software issue.
I called Apple and they were wonderful. Here was the fix: I had to uninstall ALL components of iTunes and reinstall. The first time it didn't work because I had not uninstalled everything. The second time was fine....both iPod and iPad are recognized again. The directions for the uninstall process can be found on the Apple website.
Hope this helps,
I had this problem with my PC (windows 7, 64-bit) and my iPad. After messing with it for a long time, I finally found the answer (bad USB driver). The following two step process should help resolve these kinds of problems more quickly.
The first step is to verify that the iPad (or iPhone) is really connected to your computer. This can be (really) checked using a program called USBDeview. You can get this (very small) program from http://download.cnet.com/USBDeview/3000-2094_4-10614190.html or http://www.nirsoft.net/utils/usb_devices_view.html. Don't worry, it's not Spyware or Malware.
Just run the program and sort on the 'Connected' column. If your iPad or iPhone doesn't show up as Yes (under 'Connected') then your iDevice is not properly connected to your computer. Could be a cable problem. Could be an iDevice problem. Could be a USB hub problem. Note that your iDevice might be listed as what it is (iPad or iPhone) or it might be listed as 'Apple Mobile Device USB Driver' in the 'Description' column.
Apple has a number of ideas to resolve this sort of basic connectivity issue, including switching USB ports, resetting your iDevice, rebooting your iDevice, rebooting your computer, etc. You will need to try them until your iDevice shows up in USBDeview as 'Yes' under Connected.
If you iDevice shows up as 'Yes' under connected, it should also be visible in the Device Manager (found in the Windows 7 Control Panel under Hardware and Sound). You might find it under Portable Devices or it might be under Universal Serial Bus controllers.
The iDevice may or may not show up in the Windows Explorer. On some machines it does, on others it does not. Why is not clear.
If the Idevice is properly known to Windows and iTunes can't see it, then any number of other things could be wrong. Apple has a list. See the very useful page over at http://support.apple.com/kb/TS1538. Testing shows that the Apple Mobile Device service must be running. Check this using Task Manager (started by right clicking the taskbar). Note that the iPod service and the iphlpsvc service must also be running. These services have different names under the Processes table versus the Services tab of Task Manager.
AppleMobileDeviceService.exe - Apple Mobile Device
iPodService.exe - iPod Service
ItunesHelper.exe - iphlpsvc
Step 4 of http://support.apple.com/kb/TS1538 checks if the Apple Mobile Device USB is installed. This is essential and a common source of problems. In at least some cases, Windows will install the 'MTP USB' driver. Indeed, Windows will reinstall this driver if you uninstall it. The MTP USB driver is essentially a Windows bug (possibly caused by Microsoft). You must replace the MTP USB driver with the Apple Mobile Device USB Driver. Step 4 explains how to do this. Note that you must use the 'Have Disk' approach. Otherwise, Windows will just reinstall the invalid MTP driver.
The Apple doc indicates that you can find the correct driver at C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers. Perhaps this is correct on some systems. You may find the correct driver in C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
iTunes could make this a lot easier by checking if the iDevice is known to Windows (what USBDevier does) and if the Apple Mobile Device USB driver is properly installed for the iDevice. Sadly it doesn't perform either check. Note that iTunes does if some of the related services (see above) are actually running.