Q: Today, 01/23/2014, I tried updating iTunes, as I got a messsage that update was available. The update did not download correctly the  message to uninstall iTunes and reinstall it. After the uninstall and reinstall I got an error message, please help

I had this problem as well but found the soultion on another post from turingtest2 - it worked for me:

Go to Control Panel > Add or Remove Programs (Win XP) or Programs and Features (Later)

Remove all of these items in the following order:

• iTunes
• Apple Software Update
• Apple Mobile Device Support
• Bonjour
• Apple Application Support

Reboot, download iTunes, then reinstall, either using an account with administrative rights, or by right-clicking the downloaded installer and selectingRun as Administrator.

See also HT1925: Removing and Reinstalling iTunes for Windows XP or HT1923: Removing and reinstalling iTunes for Windows Vista, Windows 7, or Windows 8

tt2

You can use Revo Uninstaller (in Advanced Mode) to Remove iTunes and  all its component from the root of your computer and then you can try  installing a fresh updated version of iTunes on your Computer.

You will find the Trial version of Revo Uninstaller from the below Link :

http://www.revouninstaller.com/

Note : Use Advanced Mode when searching for leftover files and Select All and Delete All.

Delete all the Apple files in the below given order :

1. iTunes
2. Apple Software Update
3. Apple Mobile Device Support
4. Bonjour
5. Apple Application Support (iTunes 9 or later)

And use the below link to download fresh copy of Updated iTunes :

http://www.apple.com/itunes/download/