A new one on me.
I see three copies of that file myself, in the following locations:
- C:\Program Files\Common Files\Apple\Apple Application Support
- C:\Program Files\Common Files\Apple\Internet Services
- C:\Program Files\iTunes
You could repair Apple Application Support or iTunes if the first or last are missing. I'm not sure which component is responsible for the Internet Services folder but it could be Apple Application Support too.
Otherwise 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.
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.
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