操作系统概览：从DOS到Windows和Linux的比较及应用-优快云博客

I. Sign-in Result

Let’s take a look at the screenshot of the sign-in result.
There are thirty nine students in our class. This time thirty five student have signed in and four students have not. Three students asked for leave because they are preparing for the coming competition. Only one student is not here and did not ask for leave, so he is absent.

The Operating System is a kind of system software that manages hardware and software resources of a computer and provides a user interface to operate on the computer.
User interfaces fall into two categories: CUI (Character User Interface) and GUI (Graphical User Interface)
CUI operating systems require users to remember quite a few commands to operate on the computer and are not very friendly to ordinary users. Many ordinary users like to use GUI operating systems because it’s very easy and convenient for them to operate on the computer by using a mouse and need not remember any commands.

1981 – The Wintel era began.
$\mathrm{IBM-PC}\begin{cases} \mathrm{Intel\ CPU}\\ \mathrm{Microsoft\ DOS}\\ \end{cases}$
DOS - Diskette Operating System
We can use dir command to display the information of directories.
Look at the above screenshot. The current directory is C:\Users\Administrator>. If we want to know what subdirectories and files this directory contains, we can use the dir command to get the information.
We know that there are four files and thirty subdirectories in the current directory.
Task: Create a new directory named computer in the current directory.
mkdir means make directory
Task: Rename the computer directory to 计算机 directory.
rename <old name> <new name>
Task: Copy the 计算机 directory to the root directory of D drive.
xcopy <source directory> <target directory>
Task: Move the D:\计算机 to the root directory of E drive and rename the name to computer.
Access has been denied. How can you solve this problem?
Task: Delete the D:\计算机 directory.