Here is what i did:
Start - log off - switch user
Log on to a user profile with working settings (a user that can download) I used another user account (login) on the same PC, which is recommended, but it may work with a working user account from another PC, whth the same windows version).
Start regedit, browse to "HKEY_CURRENT_USER\Software\Microsoft\Windows\Curr entVersion\Internet Settings\Zones"
Click "file" - "export", choose e filename e.g. "working security settings.reg", and save it.
Switch back to your user, with the bad security settings, and open regedit.
Browse to the same key: "HKEY_CURRENT_USER\Software\Microsoft\Windows\Curr entVersion\Internet Settings\Zones", and rename (or delete) zones, to sometheng else,e.g. zones_err. (Exporting the bad zones folder to a "bad security settings.reg" may be a good thing to do, in case of errors during this operation.)
Then import the "working security settings.reg" file you just exported from the working user profile. Just by doubleclicking on it.
It shoud be working now. (I didn't need a restart for it to work)
If it's a problem to find a working user profile, post a reply and i'll try to give you my reg file.
Good luck!