cannot install iTunes 11.1.3 update on my Windows 7

For whatever unknown reason, iTunes 11.1.3 update has and continues to be able to "auto download" without a problem, however the new download cannot not complete the update sucessfully stating an error in the software exists. This never happened with iTunes or Apple downloads before. I am running the program on my Windows 7 Ult. 64 bit VAIO Laptop. I have computer saavy, still, I am totally baffled as to what I should do. I'm thinking of uninstalling the itunes version I have with windows uninstaller program and then re-installing the newer version. I hesitate for only one reason. Would first like to know why this update is being rejected to begin with.. Oh heck, I bet this has something to do with TuneUp 2014's "under developed" temporary program deactivator service. While TuneUp Utilities provides good basic programs to clean, maintain and stylize duldrum system icons, there are also some not so good utilities, incliuding certain aspect usage of good utilities which can demolish a healthy computer without warning. itI'll be back with my fiindings and hopefully you will have shared your observations too!