Upgrading a computers operating system will not touch the personal data on the computer. It is always advisable to keep a back up of your data in case of disk failure.
data files
Sometimes when upgrading the OS of your computer there is a risk of losing the data on your computer even with minor upgrades. it is always suggested to back up the contents of your computer just in case your data did happen to get erased.
Because there is a possibility of data loss, and backing up will prevent this. It is worth doing if you value the files on your computer!
If you are upgrading to Windows 8 from an older Windows version like Vista or 7 you should not lose any files as Windows has developed the transition to be nice and smooth. If you are clearing off the OS completely and manually installing Windows 8 then it is recommended to have a backup of your files.
When you install a 64 bit OS on a system with a 32 bit OS you MUST do a clean install. An upgrade is not possible. This means that all data on the drive will be lost and must be backed up before proceeding.
If you are upgrading from an older version of Windows as in 7 or 8 you should lose nothing. If you are clearing off your current OS and installing Windows 10 by yourself then you will lose everything as your files are saved in the Windows "Files Explore". It is recommended to make a backup before doing a clear wipe.
How many licenses are usually included when you purchase applications or OSes
When upgrading and you want to keep files and settings from the previous system, use Migration Assistant. Don't do a clean install, which will erase the first system.
The Entire Data of your Operating System, I Wouldn't Delete this if I was you.
An operating system is the software that runs your machine such as windows / linux / mac. So if you were to upgrade it you are simply upgrading to a newer version
Operating System (OS) files do NOT hold data for your personal use. Any data in an OS file is used STRICTLY by the OS. A database system is used for storing data of any kind. A text file is not stored data, so you wouldn't use a database for THAT. But a dictionary of words used in the text file, along with their definitions, could use a database. Even pics can be stored in a database, and even a list of other files can be stored in a database. by:Mohammed Abu Lamdy
Linux Ubuntu and Apple Mac OS