How does the "touchpad" work perfectly until I open a document?

The document-opening trigger is useful, but it does not establish whether the touchpad itself fails or the application stops responding. Start with a test document and save your work before troubleshooting.
Compare a blank document in the same app, another document app, and an external mouse. If both pointing devices freeze in one application, investigate that app rather than immediately changing touchpad settings. If only the touchpad changes, observe whether the problem starts when you type, rest a palm near it, or press the laptop’s touchpad shortcut.
Record the laptop model, Windows build, touchpad driver version, and affected application. Microsoft recommends updating touchpad drivers through Windows Update or Device Manager; use the manufacturer’s supported package where required for that model.
Change one setting at a time and keep its previous value. Avoid broad input-device removal or resetting Windows. If updating fails, provide comparison results to the manufacturer or application suppor