Download the fileassoc.txt file here (you may want to right click and select Save As). Look up the file extension that you wish to correct. The entries are in the format of:
Use your mouse to copy the line for the association you wish to restore. Then click Start, Run and enter CMD. A Command Prompt window will open. Right click in this Window and select Paste. Then press Enter.
You can download a BAT file (zipped) that will restore all of the “default” associations that Windows XP ships with. It will not restore those file associations created by 3rd party applications. The BAT file can be downloaded HERE.
Note: This does not repair a damaged association. If the “exefile” (.exe) Registry key in HKEY_CLASSES_ROOT has been modified to run ABCDEF.EXE rather than EXPLORER.EXE for executable files, then EXE files will still run with ABCDEF.EXE. This command only restores the Default association for the file type.
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