I recently updated from the 1.3 beta to the 2.0 version of Audacity and so far everything seems fine except it broke Audacity being the default program for .wav files. And despite using the open with>browse, choose default program, etc. options audacity is not even listed as a choice for opening the files. Running Windows 7 64 bit. Quick google search shows that this problem happens sometimes with programs and I was hoping someone may know of a solution. File>Open and drag/drop works for opening them, it’s just adding it to the default list to simplify things isn’t working, and after several searches and attempts at fixes I’m stumped with no change.
Don’t despair, we can fix this 
Do you still have Audacity 1.3 beta installed?
Don’t go mad trying to fix it, the solution will be quite straightforward.
Just to help me explain what you need to do, how would you describe your level of computer expertise?
Well on a basic level I’m pretty skilled. No, the beta is no longer installed. Just trying to make audacity the default once more when you right click a file>properties>opens with- Regardless of what I do, audacity never appears on the list.
Uninstall all versions of Audacity using Control Panel > Programs and Features
Download and install a (free) copy of Ccleaner
Run the registry cleaner that is included in Ccleaner (to be safe, don’t miss out the “backup registry” step).
Reinstall Audacity 2.0.
The problem should now be fixed.
Bam. Thankyou. I wasnt aware ccleaner could solve this issue or I would’ve done it earlier. Out of curiosity, what’s the technical reason for why this works?
You added an item of personal customization to the Registry (associating the .WAV files with your installed copy of Audacity). When you uninstalled Audacity, the uninstall process knew nothing about what you had done and so it left entries behind in the Registry that were pointing to the old version of Audacity (which no longer existed). You couldn’t make a new association of the .WAV files until the old, redundant and broken links were removed from the Registry. We’ve had several long, detailed discussions about this subject, under different threads here on the forum, since v2.0 was released.
The lesson to be learned seems to be that “Uninstall” of a particular product doesn’t uninstall everything: it only uninstalls that which it knows about.
Basically what PGA wrote.
The problem is really a Windows bug rather than anything to do with Audacity. We are currently testing an easy method for users to fix the problem if it occurs, but for now this method using Ccleaner seems to work well.