Error installing bonjour?

Hi,

I have had this error message for ages when i try to install itunes or bonjour. when i am downloading it, it comes up with error writing to file: C:\Program Files(x86)\Bonjour \Bonjour.Resources\da.lproj\AboutBonjour.rtf. Verify that you have access to that directory.

I have ran a disk check using the chkdsk command on both of my drives. I have also ran it is a admin and i am sure i am downloading the latest version. I have clear it completely and tried to reinstall it but it still comes back with the same error message.

I am using windows 8.1.

Thanks

--Ed