It looks like the main thing they recommend is rebooting your computer and right-clicking on the iTunes Store and "Check for Available Downloads". If this doesn't work, then examining http://support.apple.com/kb/HT1725 (mentioned below) may help. > From: iTunes Store <http://www.apple.com/~iTunesStoreSupport> > Date: Wed, 8 Apr 2009 16:32:22 -0700 (PDT) > > Dear Noelle, > > I understand that you were unable to download your purchases. There was an > error message stating "A required iTunes component is not installed (-42401)". > I definitely understand how this can be an inconvenience for you, having some > software preventing you from enjoying your purchases. My name is Rashida and I > am more than happy to work with you until everything has been resolved to your > satisfaction Noelle! > > I am unable to find anything on the error code that you got on your computer. > But I have reposted the item back to your account. I would recommend you do > some basic trouble shooting, like sign out from your iTunes account and then > shut down your computer and then restart it. Then please follow these steps to > download the item: > > 1) Make sure you're using the latest version of iTunes. It can be downloaded > free of charge from the Apple website: > > http://www.apple.com/itunes/download > > Note: Installing the latest version of iTunes will not affect your library or > any items in your account that you haven't downloaded. > > 2) Open iTunes. From the Store menu at the top, choose Check for Available > Downloads. If you're unable to upgrade and are using iTunes 7, the option will > say Check for Purchases. You can also click this link to do the same thing: > > https://phobos.apple.com/WebObjects/MZFinance.woa/wa/checkForPurchases > > 3) Enter your account name and password, then click the Check button. > > The missing item should begin downloading and appear in your Purchased > playlist. If you receive an error message while downloading, try again after > turning off any firewall or web-accelerator software that you may have > installed. If the download process is interrupted for any reason, it should > resume once you reopen iTunes. > > This article provides information about resuming interrupted downloads: > http://support.apple.com/kb/HT1725 > > If you don't see the item in your iTunes Library, please include this > information in your response to this email: > > - The name of your Internet service provider (ISP) > - The type of Internet connection (such as dial-up, cable modem, or DSL) > - Any troubleshooting steps you may have taken > - Any error messages you may have received > > I hope this helps you. If you need further assistance or have any questions, > feel free to reply to this email and I will be happy to assist. It was a > pleasure assisting you Noelle. We here at the iTunes Store appreciate your > business. > > Sincerely, > > Rashida > iTunes Store Customer Support > > Please Note: I work Tuesday -Friday 9.30am-6.30pm CT > > Thank you for allowing me the opportunity to assist you. You may receive an > AppleCare survey email, any feedback you provide would be greatly appreciated. > > Customer First Name : Noelle > Customer Last Name : > email : http://dummy.us.eu.org/robert > Web Order # : MHV5FM3M7 > Support Subject : I didn't receive this playlist > Sub Issue : Incomplete download > Comments : iTunes Account Name: noelle > Platform : iTunes/8.1 (Macintosh; PPC Mac OS X 10.4.11) > PlayList Name : No Line On the Horizon > Comments: > I purchased this album, but got the dreaded "We could not complete your iTunes > Store request. A required iTunes component is not installed (-42401)" before > the album got downloaded. >