I can not download itunes to my windows 10

You can download just about any windows version of iTunes from the links here:

Troubleshooting issues with iTunes for Windows updates

Thanks to turingtest2, it is also a very handy troubleshooting guide for most common iTunes for Windows problems.

Installing a new version of iTunes should not affect your previous song library. But as the above guide points out, it is always a good idea to backup the library first.

Once you have installed iTunes see Recover your iTunes library from your iPod or iOS device for advice on retrieving media from any device, backup, old hard drive, or purchase history.

tt2