Quickest way to restore computer after reinstalling operating system? (all old files are in the Windows.old folder)

Long story short but my OS was corrupted and the only way to get my computer (Dell XPS 8900 running Windows 10) up and running was to reinstall the OS from USB and port all files to Windows.old. All the files are there but all the software is not installed. Is there a quick and easy way to get everything back to the way things were before the reinstall? Or do I need to manually restore things one at a time?