I followed these steps to resolve my Windows Phone 7 sync issue with Zune software on my Windows 8 Laptop. Most of the steps are same from this page: http://support.microsoft.com/kb/2468307 but my issue wasn’t resolved following all rules and restarting phone with battery removal as well as restart of computer. Please note: Deleting a certificate can create issues with owner ship of files or data, and just because this solution has worked for me, it may not work for you. Use at your own risk. Close the Zune software and disconnect your phone from your computer. Open Certificate Manager . To do this, click Start , type certmgr.msc in the Start search bar, and then press your Enter key. Windows 8 users: On the Start screen, type Certificate , tap or click Settings in the right column, and then tap or click Manage computer certificates . In the pop-up window, tap or click the Personal folder in the left column, and then double tap or double click the Certificates folder in the