Trouble installing MS Encarta 2005

[KayTee]

When I try to install Microsoft Encarta 2005 on Windows XP SP2, at the end I get an error message telling me that it can't install a font and that i should check if I have the sufficient permissions to install fonts but my account is administrator and there are no other accounts and I have tried turning firewalls and antivirus off, does anyone know what the problem might be? I wonder if it's some security feature I have to switch off in Windows?