Q: iTunes says there is an update 10.6.3 but when I click to update nothing happens?

I don't know what is going on now. It was working perfectly for 4 days. Now it's back to doing the same old dysfunctional idiocy. Apple BETTER get its act together or make an announcement that they are having an issue. This is absolutely intolerable!!!!! it looks like a Windows Tablet or Google tablet for me in the future.

I also cant get the update for 10.6.3 to download. 

Im having similar issues Ive been battling the last few days. When I tried to update the latest itunes, it was saying that resource network was unavailable. Almost all forums I researched about this error said to delete all itunes related files with windows utility then reinstall. I have refrained from this because I dont want to take the chance of losing all my content and the hassle of reinstalling all my files. Well today, I have a new error: I go to check for updates and  it shows that a new version is available BUT nothing happens when I click to download. Not even the error I was getting before. This is extremely frustrating and feeling helpless. Any recommendations what I can do to fix this without deleting and reinstalling? PLEASE!! thanks

I had the same problem. It must have been going on for some time because when I checked the version of Itunes I was still in 10.6.1. After trying three times to update and failing, I went to the following url: http://www.apple.com/itunes/download/ and downloaded from there the 10.6.3. Seems to be working fine. Have a try

Looks like it may be an issue with their CDN not having proper catalog (or not giving out proper catalog?) on all service points. By luck i found one that worked, 63.80.242.43. Update your hosts file to include

"63.80.242.43    swcatalog.apple.com"

For those of you rightly paranoid by adding an IP to your hosts file from a forum post on the internet, http://whois.arin.net/rest/net/NET-63-80-242-0-1/pft will show it is Akamai (valid CDN).

After updating this locally, SoftwareUpdate.exe was able to work without issue every time i closed and reopened.

To udpate your hosts file in windows:

1. Open command prompt (if windows 7/vista, right click and open as administrator).

2. Type in  "notepad c:\windows\system32\drivers\etc\hosts" (without the quotes).

3. Enter in a new line on the bottom of the file with "63.80.242.43    swcatalog.apple.com" (again, no quotes).

4. Save. -- If you get an error about it being open already or you not having permission to save, you likely did not run as admin.

5. Run software updater.

Hope this helps others out there!

So I have a similar problem - could not update to 10.6.3 itunes - keeps saying corrupt file - so as per b noir downloaded  10.6.3 directfrom apple.com/... and now am wondering if installing that will wipe my existing movies songs and settings held by 10.6.1 ???

What did you end up doing after you downloaded 10.6.3 from apple - did you install it or somehow update to it?

So I have a similar problem - could not update to 10.6.3 itunes - keeps saying corrupt file - so as per b noir downloaded  10.6.3 directfrom apple.com/... and now am wondering if installing that will wipe my existing movies songs and settings held by 10.6.1 ???

What did you end up doing after you downloaded 10.6.3 from apple - did you install it or somehow update to it?

Installed it, following the on screen instructions. I guess it updated upon the existing version as it has not affected at all my settings, let alone the media I had within it.

bboling's solution worked for me: adding Akamai's IP address to my host file fixed the issue. This is a DNS registration issue that Apple needs to resolve. End users have no control over this, other to institute a work-around such as this.

How do I do this exactly?

The same update failure is happening with iTunes 10.7.  With 10.6.3, iTunes eventually allowed an update, but whatever the problem was it was not fixed since it is back with 10.7. 

Hi all, please use bbolling's suggestion to edit yoru host file.  It will solve your issue.  It did so for me.

Cheers,

Ken