Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

This question already has an answer here:

I had a file that Windows did not recognize. It was called abc.per. This is the correct extension for the file. The file does not open in any known Windows programs either (this is also not a problem). For some reason, I changed the file to always open with Notepad.

Now I want to get rid of the fact that it always needs to open with Notepad, but Windows just doesn't allow me to get rid of this behaviour. I tried to rename the file in which case it loses its extension, that is, per.

How do I remove the extension and restore the default behaviour of the file?

I am on a 64-bit Windows 7 system.

share|improve this question

migrated from stackoverflow.com Jun 19 '13 at 11:09

This question came from our site for professional and enthusiast programmers.

marked as duplicate by Karan, Tog, pnuts, tombull89, Journeyman Geek Jun 20 '13 at 11:25

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add comment

1 Answer

I was able to solve the issue. It was quite simple. I needed to go into the Windows Registry and remove the default associated with the extensions. The Super User post How do you remove a default program association for file types in Windows 7? is useful.

share|improve this answer
add comment

Not the answer you're looking for? Browse other questions tagged or ask your own question.