New
#1
Yes. Previous is Windows.old, Temporary is upgrade files which are no longer needed when upgrade has been done.
Hey Stuart, :)
Sure you can delete them in Disk Cleanup if you like.
Here are some other ways to delete the Windows.old and $Windows.~BT folders if needed. I like Option 4 best.
Delete Windows.old Folder in Windows 10 Windows 10 Installation Upgrade Tutorials
lol wow! Sorry I just had to comment on this. Your previous Windows folder is 45 GB big? That was a huge waste of space just sitting there on the computer. Good thing you freed that up, right? lol