Q:

What are the advantages and disadvantages of a dual-boot Windows installation?

I want to install Windows in a dual-boot configuration on my laptop, so I want to know about the advantages and disadvantages of doing so.
The primary questions are as follows:

Are the folders between each OS different?
If I install some program that is only compatible with Windows 8, will it be blocked in my Windows 10 or will it make Windows 10 crash?

A:

Starting with Windows Vista, each copy of Windows will require a dedicated partition of your disk. If you try to install Windows on a partition in which there is already a Windows, assuming there is enough space in that partition, Windows Setup will move files and folders of the existing copy of Windows into "Windows.old" folder. These include "Windows", "Program Files", "Users", "ProgramData" and "PerfLogs" folders.
Because of this, the installation of an app in one version of Windows in a multi-boot configuration will not impact the other version of Windows in the other partition.
Still, it is reported that in a dual-boot configuration, System Restore does not work properly. According to Wikipedia:

Changes made to a volume from another OS (in case of dual-boot OS scenarios) cannot be monitored. In addition, dual-booting different versions of Windows can disrupt the operation of System Restore. Specifically, Windows XP and Windows Server 2003 delete the checkpoints the Windows Vista and later have created.[21] Also, checkpoints created by Windows 8 may be destroyed by previous versions of Windows.[22]

