How to prevent AutoCAD from interfering with screen savers

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AutoCAD's default file association for SCR extensions can disrupt Windows screen saver functionality by overriding system registry settings. This occurs because AutoCAD registers SCR files as AutoCAD Script Files during installation, conflicting with Windows' native scrfile handler responsible for screen saver execution.

‌Root Causes of Interference‌

1. ‌Registry Override‌
   • AutoCAD modifies HKEY_CLASSES_ROOT\.scr to point to AutoCAD.ScriptFile, bypassing Microsoft's default scrfile association.
   • This forces the system to launch SCR files via acad.exe instead of scrfile.exe, disabling screen saver previews and controls.
2. ‌Execution Context Mismatch‌
   • Screen savers require specific Windows API calls (e.g., SetThreadExecutionState), which AutoCAD's script handler cannot replicate.

‌Preventive Measures‌

‌1. Manual Registry Adjustment‌

• Navigate to HKEY_CLASSES_ROOT\.scr and:
  • Change the (Default) value from AutoCAD.ScriptFile.1 back to scrfile.
  • Delete any AutoCAD-related subkeys under .scr.

‌2. File Association Reset‌

• Open Control Panel → Default Programs → Set Associations.
• Locate .scr and set the default program to Microsoft Screen Saver.

‌3. AutoCAD Configuration Tweaks‌

• ‌Custom Installation‌: During setup, deselect Register SCR files to avoid conflicts.
• ‌Command Line‌: Execute FILEDIA=1 and SCRIPTPATH to reset script file paths.

‌4. Group Policy Enforcement (Enterprise)‌

• Deploy registry templates to enforce .scr association with scrfile.exe across all workstations.

‌Verification Steps‌

• Test screen savers in Display Properties.
• Confirm SCR files launch with Test and Configure options intact.

By proactively managing file associations and registry settings, users can maintain both AutoCAD functionality and native screen saver compatibility. For persistent issues, restoring AutoCAD to factory defaults or using the /p startup parameter may be necessary.