Win7 computer can't choose default open mode for program?

Generally speaking, for the installation of a good program, the system has the default mode of opening, such as the use of Word to open the relevant documents, open the table in Excel, with txt open Notepad file, but sometimes, some of the less commonly used programs appear, will make the computer can not recognize, Even the default open mode is not a good fit for the current program, and this time, we need to reset the way the program is opened. However, the recent small series found a strange phenomenon, some Win7 32-bit system can not set the way to open the program, how to solve this problem?

1. Let's just pick a file for example, as a small series of the selected PDF file, if the computer is not recognized, can not set the default mode of open, when we double-click it, it will appear as shown in the image below the interface, we need to reset.

2. However, the choice of open mode is limited, and there is no suitable for our PDF file open program, this time, we will click on the bottom of the browse button.

3. And in the next window, the program you want to choose is still not there, let's just press Win+r to open the computer's running window and enter regedit and click Return.

4. After opening the computer's Registry Editor window, we locate the Hkey_current_ in the menu on the left. Usersoftwaremicrosoftwindowscurrentversionexplorerfileexts.pdf, and then delete all items except the default project Openwithlist subordinates.