When the computer is just started, some system programs must be read into the memory from a disk before it can work normally. We call this disk the startup disk.
Usually, we use a disk or C disk as the startup disk. In special cases, other drive letters of the hard disk and optical disks of a few computers can also be used as the startup disk. You need to use the sys command to create the startup disk. See the command section below.
When starting the DOS system, first read two system files IO from the startup disk SYS、MSDOS. Sys, and then find and execute config. Sys in the root directory of the boot disk SYS、COMMAND. COM、AUTOEXEC. Bat three files. Where io SYS、MSDOS. Sys and command Com these three files are indispensable, otherwise the computer will not start normally
CONFIG. Sys and Autoexec Bat files are used to configure the system running environment and automatically execute some commands. They play a vital role in the running performance of the computer and the drivers of many devices. We can modify their contents according to our own needs,
autoexec. Bat is called automatic batch file. It is a kind of batch file. Because it will run automatically when DOS starts, it is called automatic batch file. You can put the program you have to run every time you start the computer in it.
If the computer cannot find these two files in the root directory, it can run, but many complex software and devices will not work normally. Such as optical drive, sound card and windows program. Therefore, beginners should pay attention not to delete the above files, otherwise, the computer will not work normally.