Q: sign in to iTunes

Hello Martiff3434, 

Thanks for using the Apple Support Communities!

I understand that you are not able to sign in to iTunes on your Windows computer. Are you receiving any errors or alerts when you try?

The following article explain how to sign in to iTunes on your computer as well as recovery your Apple ID or change the Apple ID password if needed. 

iTunes 12 for Windows: Manage your iTunes Store account

If you forgot your Apple ID - Apple Support

Change your Apple ID password - Apple Support

Cheers!