1. After turning on the power, before turning on the power, pay attention to the bottom or top of the display, press a key to enter the motherboard settings (this key is different for different brands of computers, so pay attention to it, there are prompts on the screen), and then restore the system;
2, buy a CD-ROM installation system, this pure fool-like operation, I don't need to say it;
3. Use the virtual CD-ROM to install. First, download the virtual CD-ROM drive (usually Damon tool) and the CD-ROM image file of the operating system you want to install (that is, the file in iso format). The CD-ROM image file of this operating system can be downloaded in win7 House or win7 World (both XP VISTA WIN7), and then the virtual CD-ROM drive is installed, and the image file is loaded with the virtual CD-ROM drive, and then installed.
There is also the activation of the operating system. If the downloaded image files are installed, some of them need to be activated. I didn't install XP and VISTA. I use win7 Ultimate Edition (the operating system I bring is genuine Vista). Win7 Ultimate was downloaded from win7 House and activated by serial number. Now those serial numbers called the magic key can't be used, so I can only activate them with software. There are many activation software, including Win 7 House. You can go and have a look. Activation is a fool's operation