Hello, I had a similar problem and it turned out to be .MSI files not being compatible with the SYSVOL location for software installation in XP /2003 server : https://support.microsoft.com/en-us/help/889710/you-receive-a-this-installation-package-could-not-be-opened-error-mess
I created a dedicated share for my GPO and it worked great.
Hope this helps !