Windows 10，Excel 2007，必须按Alt-Tab-Tab才能切换到其他窗口，而从其他窗口，切换到Excel，只要按一次Alt+Tab即可。解决方法：
把下面的内容保存为一个aaaaabbbbb.reg文件（不包括-----内容），双击导入注册表，重启电脑即可。
Why do I have to hit tab twice to Alt+Tab away from Microsoft Excel in Windows 10?
In other apps, when I hit Alt+Tab it switches to the previous app. Before I actually release the Alt key I can see a list of windows as well and the previous windows is selected. But in Excel 2010 (Professional Plus, if that makes any difference) hitting Alt+Tab and not releasing Alt shows Excel still selected, and in any case I have to hit Tab an extra time to switch to the previous application. (Alt+Tab+Tab) Furthermore, the iconized view showing my spreadsheet only takes up about 1/3 of the height available.
Needless to say this throws off my workflow because switching between Excel and another application is inconsistent, requiring an extra keystroke to switch away but not to switch back. Is this a bug in Excel, or is there some option that I need to change to get the default behavior? What's going on here?
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
"AltTabSettings"=dword:00000001
上面的注册表代码，会把Win10的程序切换改成经典的方式，不带预览效果，如果不喜欢的话，就不要用。
或者运行指令，or rum cmd command：
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer" /v AltTabSettings /t REG_DWORD /d 1 /f
这是win10带预览窗口的一个小bug，你要么等以后微软出补丁，要么先用经典方式。