I get this same issue. When ever I try to start iTunes, it just hangs, and then doesn't even open. Im running 64bit Windows 7, and I have used iTunes with 64 bit versions before with no worries. It got to the point,that when i tried to downgrade to 15, I couldn't even uninstall 10.6. When I went to Start>Control Panel>ADD Remove>Itunes, the installer itself again, would hang, then windows would crash with a "Windows is not responding" message. So, I'd thought i'd be nifty and download the 10.6 installer again, and use it to uninstall the current iTunes 10.6 and see if that would work. IM currently in the process now, and have been waiting for at least 10 minutes, and still no show of the installer. Im running a gaming rig, so there is no issues with RAM, CPU, etc. Its a software issue, a MAJOR one at that.
I'd doubt it would be a 64/32 bit compatability error, as otherwise, the installer itself, would've cracked the ***** depending on which version you of 7 you are running. I'm tipping an internal flaw in the 10.6 release of iTunes. Ok, my work around failed. I tired to uninstall 10.6, and now it's come up with a "Another installation is in progress, you must complete that installation, before continuing this one". I ran Task Manager and noticed that there where several instances of MSI Microsoft Installer running, when there really should only be one I would assume. Why would this be?
I really do hope that someone over at Apple is getting thier *** kicked at the moment, because this is really starting to frustrate me, to the point where im looking at switching to Winamp.
I spent about 8 hours on this problem and came to the conclusion that 10.6 64 bit was not properly tested by Apple. I tried reverting back to the previous version. That doesn't work at all. I tried downloading a previous version, but their installer doesn't remove and reinstall one of the dll files, so you wind up with an old version with a 10.6 dll file and the program won't run. You can't even uninstall iTunes and less you have Administrator access set up on your computer. My solution was to restore the computer back to an earlier date, before I installed 10.6. At least my PC works fine now. However, I am unable to use iTunes because of their inproperly tested installer program. I will either wait for the next version and hope they fixed the problem, or I will switch to just using an MP3 player.