As Chris has asked, how did you accidentally delete QT? If I understand correctly, you thought you had to do that in order to update to the latest QT. I think what may have happened is that you've deleted some parts of Quicktime, but there are still some QT files tucked away in the System. They're often hard to identify, and some may be invisible.
Try using a third-party application cleaner like AppCleaner or AppZapper or CleanApp to remove ALL QT files from your MacOS. Choose Send to Trash as the option of what to do with the files. DO NOT delete them (yet).
Once you've cleaned out all the QT files, then you can then download the latest QT from the Apple site. You'll have a minor problem there in that your present Mac has, according to the SysPrefs, been using the Pro version. That costs $$.
One more thing to check is SysPrefs > Accounts > Login Items to see if there are any QT components there. As Louishen has pointed out, you'll need your Admin ID - or a Tiger Install disk - to make changes.