Win7 computer can not choose the default open mode for the program to solve

Generally speaking, for the installed program, the system has a default open mode, such as opening the relevant document with word, opening the form with excel, and opening the notepad file with TXT, but sometimes, some unusable programs appear. It will also make the computer unrecognizable, and even the default opening method is not very suitable for the current program. At this time, we need to re-set the way the program is opened. However, recently Xiaobian found a strange phenomenon, some win7 32-bit system can not set the program to open the way, how to solve this problem?
1. Let us choose a file as an example, just For example, if you can't set the default open mode if the computer is unrecognizable, when we double-click it, the interface shown in the following figure will appear. We need to re-set it.

2. However, there can choose to open the way are limited, but we did not fit the PDF file to open the program, this time, click on the Browse button below.
3. In the next window, if the program you want to select still does not exist, we can directly press win+r to open the running window of the computer, then enter regedit and click Enter. After


4. Open the computer's Registry Editor window, navigate to the HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerFileExts.pdf our menu on the left, and then remove all items except subordinate to OpenWithList open the default project.