"iTunes has encountered an error and has to close"

Question

I'm getting this error message whenever I plug in my nano or my mini. iTunes crashes. This just started happening. So far I've reset, restored, reinstalled - you name it. But nothing works.
iTunes works fine when there's no iPod plugged in.
Help?

Answer 1

well done MAJR!
just a note on the error message "itunes has encountered a problem and needs to close".
there are actually at least three different contexts in which people get this message, and the treatments will differ depending on the context. here's some info on the three most common contexts.
"itunes has encountered a problem ..." when LAUNCHING ITUNES
this is the most common time to see the message. in my experience, 90% of the time this is caused by a broken QuickTime 7.0.x. So the first thing people should check for is whether their Quicktime will launch, or whether it gives them an error message when they try to launch it.
if you get an error message when you try to launch Quicktime, the standard treatment is to swap out your QuickTime. there's actually an Apple KB doc on the problem, although the silly sausages have given the error message incorrectly in the doc (as of the 23 December 2005 revision), which makes it more difficult to find the message when you're searching for it:
iTunes 6 for Windows unexpectedly quits when opened
... that method is pretty servicable in the majority of cases, but it leaves you open to a known complication of a broken Quicktime where people can't uninstall their QT and get an error message citing their QuickTime "uninstall.log". so i usually suggest to people that they try a careful standalone QT 7.0.4 reinstall instead (which gets past the "uninstall.log" error):
download and save a copy of the QT 7.0.4 installer to your hard drive. (run the install from there rather than online.) switch off all antivirus and antispyware applications prior to the install.
Quicktime 7.0.4 Standalone Installer
known complications of QuickTime reinstalls: the most common (for QT versions 7.0.2 and 7.0.3 and iTunes versions 5.0.0.35 through 6.0.1.3, at least) is an error message citing "Error 0x80040707". in this context (again, the treatments for this error message are context dependent too), the most common cause of the Error 0x80040707 is a snarlup in the QT installation registry entries.
what typically fixes it is the Windows Installer CleanUp utility:
Description of the Windows Installer CleanUp Utility
use the utility to clear the existing Quicktime entries. then try the careful standalone QT 7.0.4 reinstall again.
other known causes of "itunes has encountered a problem ..." on launch: probably the most common of the rarer causes (if you'll pardon the oxymoron) is a rare weird problem to do with the registry and user accounts on XP machines.
to check for that, first head into your "User Accounts" control panel and create a new user account with full administrative privileges. (there's help documentation on how to do that at the left of the control panel screen.) while you're in that control panel, switch off "Fast User Switching" in your logging-on preferences.
now, log out of the old account and log into the new account. can you get itunes to launch inside the new account?
if itunes does launch inside the new account, then try an experiment (this rules out an ultra-rare "false positive diagnosis" of the registry/user-account thing). use the following technique to share the music from your old account to the new account:
iTunes: How to share music between different accounts on a single computer
if itunes still launches from the new account once you've shared the music from the old account to the new account, then you've got the registry/user-account thing.
fixing the old account might be tricky. we've had mixed success with combinations of complete uninstalls of itunes using the following technique:
Da Gopha: Stepwise clean uninstallation of iTunes
... followed by application of a Registry repair program such as RegCleaner or Registry Fix. failing that, it might be worth just "moving house" to the new account.
(there are other even rarer causes of this message on launch ... if you believe you've got one of those, best to start your own thread and explicitly explain as best as you can what the behavior is and what steps you've already taken to try to resolve the issue.
"itunes has encountered a problem ..." when IMPORTING A CD
in iTunes versions 4.9 through 6.0.1.3 this was most commonly caused by a hyperthreading problem on PCs with dual cores and dual processors. on those versions of iTunes, the workaround was to set the itunes affinity to a single core/processor. (Otto42 is our authority on that topic.) but the bug has been fixed in iTunes 6.0.2:
iTunes for Windows quits unexpectedly importing CDs on a dual-processor or dual-core computer
"itunes has encountered a problem ..." when PLUGGING IN AN IPOD
the most mysterious of the three main classes. there doesn't seem to be a common cause of this one (or at least it hasn't been clearly identified yet).
probably the first things to check up on are:
iTunes for Windows may unexpectedly quit when syncing folders of pictures with iPod
... but if no joy there, this is probably the best next port of call:
Troubleshooting an unexpected quit or restart of Windows, iTunes, or QuickTime
love, b