Why is the computer switching the operating system when it is turned on?

The setting method is as follows:

1. Click "this pc" with the left mouse button, as shown in the red box below;

2. Right mouse button, and click the last "Properties" in the pop-up options, as shown in the red box below; Degree

3. Find and click "High Answer Level System Settings" in the function bar on the left, as shown in the red box below;

4. in the system property box that pops up, select "advanced", as shown in the red box below;

5. Click the "Settings" button in the startup and troubleshooting column, as shown in the red box below;

6. In the system startup of startup and fault repair, check "Show the time of making system list in operation", as shown in the red box below;

7. Set the time as long as you think fit, as shown in the red box below;

8. after setting, click the "ok" button in the lower right corner to allow the operation to be completed, as shown in the red box below.