Problem: After removing ArcGIS for Server or Background Processing (64-bit), Python files (.py) are not associated with Python


The 10.1 release of ArcGIS for Server installs a 64-bit version of Python. At 10.1, Service Pack 1, Background Geoprocessing 64-bit was released, which also installs a 64-bit version of Python.

When either of these products are installed on the same machine as ArcGIS for Desktop, as the last product installed, the Windows file association for Python files (.py) is updated to the 64-bit version of Python.


Removing the 64-bit ArcGIS product also removes 64-bit Python. When Python is removed, the file associations for .py files are removed.

Solution or Workaround

The Windows file associations for 32-bit Python can be repaired in one of two ways.

Method 1: Perform a repair on ArcGIS for Desktop

A. From the Programs and Features option in the Windows Control Panel, select ArcGIS for Desktop and click Uninstall/Change.
B. Choose the Repair option and continue through the setup wizard.

Method 2: File associations can be manually set within Windows

• Windows XP: Follow the instructions from Microsoft Knowledge Base article 307859: How to change or select which program starts when you double-click a file in Windows XP

• Windows 7: Follow the instructions from the following Microsoft video: Change which programs Windows uses by default

A typical installation of ArcGIS for Desktop installs 32-bit Python to C:\Python27\ArcGIS10.1\python.exe. Use this Python executable when re-setting the file association.

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