No not necessarily. When you start the windows installation process there will be many question in the process. At one stage the windows installer will display all the hard drives and partitions on your computer asking you on which partition you would like put the new instillation. You can select the partition of your previous Windows, just make sure not to format that partition. If you format the partition all the data is lost, if you continue as is, the old Windows files and your Old Data Files will be placed in a directory called “Windows.old” and from there it will proceed creating a fresh copy of the operating system. Please note that all your applications will also have to be installed after windows is done with the update
