Different methods of Operating System Installation.

Generally, we use operating systems to perform day-to-day tasks. So what would you do if your OS was corrupted or lost? You will try to recover or at last, you end up reinstalling the OS.

To install the OS you need bootable media & you need boot media creation tools for the creation of bootable media.

A Bootable media is storage (can be a Pendrive, CD/DVD, etc) that holds the OS installation files. Boot Creation Tools is a tool that converts normal media to bootable media.

• It makes bootable media by adding the necessary OS installation files from .img/.iso file to normal storage/media.
• Ex: Nero, Rufus, Windows media Creation tools, etc.

Now we will see different methods which do not need any boot media creation tools for preparing a boot media.

First Method:

1. Use this when you have an OS corrupted PC and you want to install a new OS.
2. Take the OS file (mostly it will be in .ISO or .IMG format) and keep it in some folder on your android phone.
3. Then mount the OS File on an android phone using a file manager. 
4. After mounting, in file manager, you will see OS files present in the .ISO/.IMG file needed for installation.
5. Just copy all the OS files to the root level of the destination place ( on the same android phone).
   • It means the files should be in top level directories of the bootable media.
   • Ex: If the .ISO/.IMG file is in internal storage and after the ISO mounts, copy the OS files to the SDCARD root directory.
6. Unmount the ISO file after copying. 
7. Plug the android phone into the OS Corrupted PC.
8. Change the phone’s USB settings to mass storage mode so that the SDCARD will become virtually isolated from the android phone.
   • By making these PC BIOS, we will be able to detect SDCARD as a bootable media.
9. Restart the PC, select the bootable media in BIOS, and press enter.
10. Now, the PC will boot from bootable media to perform OS installation.
11. Once the OS is installed, move the files present in the parent directory to the subdirectory of the SDCARD.
    • Doing so, the PC BIOS will detect SDCARD as storage but not as a bootable media.
    • BIOS cannot search for OS installation files in subdirectories.

This method brings effective usage of smartphone external storage for creating bootable media and avoids using third-party media creation tools( such as Nero, Rufus, Windows media Creation tools, etc) to create bootable media. 

After OS installation, you can use the SDCARD (with boot files present), for different purposes, since the SDcard is not formatted with any file system and no data is lost. 

Second Method:

1. Use this method when you have multiple ISO/IMG files stored on an android phone.
2. After OS installation,  you want to boot/install another OS from the same media.
3. Copy/move old OS installation files from parent directory to a child directory in the SDCARD,
   • So that old OS installation files can be used in the future.
4. Now mount the new ISO/IMG file.
5. Copy the newly mounted OS files to the parent directory.
6. Unmount the ISO file.
7. Plug the android phone into the PC.
8. Change the phone’s USB settings to mass storage mode so that the SDCARD will become virtually isolated from the android phone.
   • By making these PC BIOS, we will be able to detect SDCARD as a bootable media.
9. Restart the PC, select the bootable media in BIOS, and press enter.
10. Now, the PC will boot from bootable media to boot into another OS.
11. Again, if you want to boot the previous OS installation files, simply copy those files and keep them in the parent directory.
    • Only one OS installation file can be present in the root directory.

The second method gives easy maintenance of multiple OS installation files on android phones.

Third method:

• Use this when you don’t want to install any OS on your PC and also use this method if you want to do data recovery from a corrupted PC.
• Live OS saves installation time and increases readiness to work on the PC.
• You can use LIVE OS for emergency purposes so that we can complete our tasks without installing the OS.
• First, you’ll need a .iso file of your Live OS which you want to use and make it bootable in a Pendrive.
  • For making it bootable, follow the first method from steps 2 to 9.
• Now, the PC will boot from bootable media to perform booting to LIVE OS.
• Once your work is done, turn off the PC. Live OS will be lost.
• Again, if you want to boot into LIVE OS, simply re-plug the android phone with LIVE OS files in the root directory.

In a live OS, viruses can’t be resident since the live OS stays only in RAM. 

As soon as you switch off the system, the OS is lost and your system is virus-free. A virus stays permanently when it is written to a non-volatile type of memory such as a hard disk.

• On the Live OS, you can recover data from other partitions (example: D Drive) even if the OS partition (example: C drive) is lost completely or the system is not booting.