A Microsoft file hosting and synchronization service.
Hi!
I'd recommend avoiding the ZIP download entirely, especially since you're dealing with a large number of video files.
There's a much easier way to transfer everything:
Install the OneDrive desktop app on your Windows PC and sign in with the account containing your Xbox clips.
Open your OneDrive folder in File Explorer, find the folder containing your clips, right-click it, and select "Always keep on this device." This will download all the videos directly to your PC without creating a ZIP archive.
Wait until OneDrive finishes syncing and make sure there are no sync errors. You should see green checkmarks next to the downloaded files.
Install iCloud for Windows, sign in with your Apple Account, and enable iCloud Photos.
Open File Explorer and drag your downloaded videos into the iCloud Photos folder. They'll upload to iCloud and eventually appear in the Photos app on your iPhone, provided iCloud Photos is enabled there.
I'd also recommend comparing the number of files in your OneDrive folder with the number downloaded to your PC before transferring them. That way, you can catch any missing clips.
The 15.6 GB ZIP doesn't necessarily mean every file was included, and 7-Zip won't be able to recover files that were never downloaded in the first place.
This method should be much more reliable, and you won't have to manually save hundreds of clips one by one.
Hope this helps!