iTunes 12 still works with Windows XP SP3 and later. You can get it here:

https://support.apple.com/kb/DL1790?locale=en_US

The direct link is https://secure-appldnld.apple.com/iTunes12/031-08058.20141016.34epp/iTunesSetup.exe

Once they have deleted this link (they eventually will), you can get it in the Internet Archive: http://web.archive.org/web/*/https://secure-appldnld.apple.com/iTunes12/031-08058.20141016.34epp/iTunesSetup.exe