An OS is installed on the computers' hard disk, inside an area called hard disk partition. There are several ways for installing a new operating system. The installation method is based on the system hardware and end-user requirements. Typically, you have four basic options for the installation of a new operating system:
We can perform a clean installation on a new computer or in those cases where there is no upgrade path between the current operating system and the new one. This type of installation deletes all data on the hard disks partition where the current operating system is installed. A new PC requires, of course a clean installation. You can also do a clean install when the current operating system installation has corrupted files or does not work properly.
Sometimes, it is also possible to perform an upgrade. When you perform an upgrade, OS configuration settings, installed programs and data are preserved. With this installation you have nothing to worry about, because you will not lose any personal data. You will just replace the old operating system files with the new, upgraded files. However, keep in mind that after the upgrade the applications and drivers that are incompatible with the new OS will not work as expected.
Another option is to install multiple operating systems on a single computer. You can install each OS inside a different disk partition and this way every OS will have its own files and configuration settings. On multi-boot installations, the users see a menu when they open their computers and they have to select the desired OS. Of course, only one operating system can run at a time.
This is relative new technique that is often used on servers. With virtualization we can run numerous copies of an operating system on a single set of hardware and create this way some virtual machines. Every single virtual machine works like a separate computer. This technology makes a single physical hardware resource to appear like multiple logical resources.
Before starting any operating system installation you have to make sure that all the hardware is certified to work with the new operating system. Also confirm that the hardware resources meet the minimum installation requirements. Moreover, when you perform an upgrade it is a very good practice to perform a virus scan before starting the installation and a complete full backup of all your personal data.
One method that helps you protect your data is this: Create multiple partitions on the hard disk and install a different OS on each partition. Then copy all your data inside an empty partition that does not contain an OS. This way you can upgrade the operating system without the risk of losing any data. Backup and recovery of data files is also easier with this design.
It is also important to decide the type of file system to use. The file system controls how the OS stores and tracks the files. There are several different file systems available. The most well-known are: FAT 32, NTFS, HPFS, ext2 and ext3. Every operating system is designed to use one or more of these file systems. There are advantages and disadvantages on every file system. Careful consideration should be made to the type of file systems supported by the selected OS and the benefits of each.
You can find several programs to modify the partitioning structure and file system of a hard drive after installation, but it is better to avoid them if possible. When modifying either the file system or partition structure on a hard drive, data loss may result. Careful planning can help preserve the integrity of the data.