Can't install Itunes

Hello,

I haven't been able to update/reinstall ITunes for a few months now. I had windows 7 (which I couldn't download with) and have recently upgraded to 10. I have followed all the steps and double checked multiple times now and Keep getting the Error 2. My iPhone shut down today and Is saying to connect to iTunes and I can't because it will not download. So now I don't have a phone. Please help me.

Thanks,

Lindsey