Re-post your question in the proper iTunes forum, either for Mac or for Windows. This forum is for asking questions about how to use these forums, not for questions about software or hardware.
What you need to do will depend more upon your computer's configuration and right now we know nothing about that. If using a Mac, get more information about your computer. Go to the Apple in the upper left corner of any window, then "About This Mac". Write down what it says about "version"and report it in your topic. Now continue to "More Info..." Copy and paste the information, but omit the serial number and Hardware UUID (if present).