Originally posted by jhessejack
When I try to unzip it says the archive is either in unknown format or damaged.
It's not a ZIP, so you can't unzip it. It's a RAR. Download a free program called WinRAR. There are other free programs that can extract RARs but I've seen reports of errors in Save Wizard after using many (not all) of them, but I know this one pretty well after a couple decades of use. It will eventually tell you your license has expired and prompt you to pay for it, each and every time you open it but you don't have to (always encouraged though).
Set WinRAR as your default program for extracting RAR files. You can also hand over responsibility for unzipping ZIPs to it...
BUT, when you make your own ZIPs, I'd do that straight through Windows' Explorer (right-click) to make it as simple as possible and eliminate the potential for small errors creeping in.