Itunes was not working correctly, and would not accept update. Consequently I have uninstalled iTunes, Apple software update, Apple mobile device, Bonjour and Apple application support 32-bit

For general advice see Troubleshooting issues with iTunes for Windows updates.

The steps in the second box are a guide to removing everything related to iTunes and then rebuilding it which is often a good starting point unless the symptoms indicate a more specific approach. When reinstalling right click on the downloaded setup file and use run as administrator. It may also help to temporarily disable any non-Microsoft anti-virus.

Review the other boxes and the list of support documents further down the page in case one of them applies.

The further information area has direct links to the current and recent builds in case you have problems downloading, or want to revert to an older version if the current one won't work properly for you at the moment. Links to the most recent builds are now at the bottom of the page.

Your library and device backups should be unaffected by these steps but there are links to backup and recovery advice should it be needed.

tt2

meryton wrote:

... I have downloaded iTunes64Setup on Windows 7 and have received an unknown error (0x80090302) with the advice to try again later! I have done this twice with the same result...

That error is typically associated with old versions of iTunes that are no longer supported by the store. Is there some reason why you do not want the current version of iTunes?

More precisely, the iTunes Store no longer supports any version of iTunes for Windows that is old enough to use on Windows Vista or XP. If you were running Windows 7, 8.1 or 10 and tried to use an iTunes version older than 12.6.5.3, then you would get exactly the same error. Apple once threatened to cut off Windows XP and Vista from the iTunes Store on May 25, 2018 (see the link posted by turingtest2), but as you probably know, it was still possible to sign in earlier this year. (As best I can figure, Apple implemented changes around October 15, 2019.) I still have an old PC running Vista myself. If you would like to read more, see the old thread https://discussions.apple.com/thread/250766202 that I posted in back in October. In any case, you will not be able to update, purchase anything, back up or sync any device using iTunes because Apple does not support Windows Vista or XP anymore, period.

iTunes would not update, and I am unable to purchase anything. I too have received an unknown error (Ox80090302), I have Windows Vista (I think). How do I fix this please ?

Windows Vista is no longer able to connect to the iTunes Store correctly. See About App Store and iTunes Store availability - Apple Support for background.

tt2