回复：电脑突然自己重启后不知是我点了什么还是自己把start manu bar从屏幕横底变成右边竖起了

First right mouse on the taskbar and uncheck "Lock the taskbar". Now click in the middle of the taskbar and drag it (move mouse to the botton of the screen) and you will see the taskbar jumps down there (not the normal drag behavior). If it is adjusting the size - you are clicking on the edge not the middle.