我們知道，未知文件格式的文件會顯示成一張白紙一樣的東西，每當雙擊此類文件時，系統會彈出打開方式對話框，而如果你之前誤用某程序打開了這個文件，那該程序就會出現在打開方式的程序列表中。比如，新建一個文件，名為，test.003，用Adobe Reader打開一次，此后每次雙擊此文件都會出現下面的對話框。那么，怎么去掉呢？
*Win+R運行regedit
*定位到HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\[file extension]\OpenWithList
*在左側列表中找到文件擴展名，比如，我們所說的.003
*在右側找到要刪除的程序鍵值，比如，我們舉例的Adobe Reader，在注冊表中的鍵值名為AcroRd32.exe，右鍵-刪除即可
附部分原文：
If you accidentally open a file with wrong program, you will notice the program used to open the file is added to the recommended program list. The reason is Windows remembers you have used the program to open it once. Once it is added, it will be there forever although it is not the correct program used to open this file. For instance, test.003 is supposed to be opened by using notepad, but if you accidentally open it with Adobe, so you will see Adobe being added to the recommended program list for all files with .003 extension. How to remove the wrong recommended program from the Open With window? Here you can remove it by doing some simple tricks.
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