is it safe to delete previous windows installations code example

Example: previous windows installations delete

/* -----------------------
As long as you have no plans to roll back to a previous version
you can delete using Disk Cleanup. (:

How to recover/restore your previous version of Windows
using the Rollback feature:
http://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/how-to-recover-restore-your-previous-version-of/76b6750c-5bb2-40bc-a7e3-f03cec62338b
----------------------- */