I am going to start your project right now. With extensive PowerShell scripting expertise, I will craft two precise scripts for silently uninstalling all Firefox and Thunderbird instances while preserving user data. These scripts will work across Windows 7, 10, and Server 2016, detect both 32-bit and 64-bit installations, and handle custom locations. I will ensure smooth uninstallation, provide a backup option for user data, and include basic error messages for any issues.