Win7 How do I cancel a file association?

Win7 How do I cancel a file association? Recently a lot of Win7 users asked the small, why in the open PDF file when the wrong program, and then open the relevant PDF file also open the wrong, how to solve this method. The reason for this is also very simple, is the association between files, so as long as the cancellation of the file association can be, the next small series to tell you how to cancel the file association.

1, click Start Menu-run, and enter "regedit" in the running column to press ENTER;

2, enter the Registry Editor, click on the order to open: "Hkey_current_usersoftwaremicrosoftwindowscurrentversionexplorerfileexts.pdf;

3, the "Openwithlist" registration, the right window in addition to the "(default)" Outside the registry key to delete all, and finally delete the "Userchoice" registration;

The above is Win7 open PDF file Associated error processing method, through the above steps, you can open the PDF file.