"Hi, there. I can't switch programs using the methods introduced in 2 Ways to Switch Apps on Windows 8/8.1. Can you kindly explain what the reason is? Hope to get your reply soon."
The most reasonable explanation is that someone has made changes to the related setting (i.e. Turn off switching between recent apps) in the Local Group Policy, as shown in the following picture.
If it is the case, you can disable or do not configure this setting according to the steps below.
Video guide on how to allow switching apps in Windows 8:
Step 1: Open the Local Group Policy Editor.
Step 2: Go to edit the setting specified.
FYR, the path to find it is User Configuration/Administrative Templates/Windows Components/Edge UI/Turn off switching between recent apps.
Step 3: Disable or do not configure this setting.
Choose Disabled or Not Configured, and click OK to finish the setting.
Now, try this method and see if you can successfully switch the apps on your computer.
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