You should use the same or later version that you had previously installed. iTunes 12.1.2 is the last version to work with Windows Vista* - direct links to the installers as follows:
The third of these - which is actually the 32-bit application with a 64-bit installer - should be used if you get a warning about video card incompatibility when you install the standard 64-bit version, but also may resolve issues with playback, QuickTime compatibility, and problems with some third-party applications (including Outlook).
* acknowledging that all versions of iTunes since 11.1.5 have had a problem with Data Execution Prevention errors in Vista.