Greetings, N29TEL.
It appears that you're having a problem purchasing songs in iTunes for Windows on your Windows 10 PC. When you try, you get a message that the network connection was reset. We're glad to help with this.
First, sign out of iTunes for Windows, then restart your PC. Once it's back to the Desktop, sign back into iTunes and see if you're able to purchase the song.
If you can't access the App Store or other Apple media services, or can't edit your payment information - Apple Support -- Scroll down the the section titled "If you can't access the iTunes Store on your device". Make sure that your PC is updated along with iTunes for Windows.
If you can't connect to the App Store, iTunes Store, or Apple Books - Apple Support -- If you still can't purchase a song, use the steps in this support article. Some of them aren't specifically applicable to your Windows PC, so you may need to search for the settings.
Let us know how that goes.
Take care.