Error message during JAVA update 7 OS 10.5.8 Software

This may not be something this forum can answer but I am getting the following error when attempting to update JAVA on my MacBook (others computers working fine) .

Error:

Installer could not create the folder "/private/tmp/JAVAForMacOSX10.5Update7.pkg.3151331d7UI"

Also, I tried to update Excel and got this error:

Installer could not create the folder "/private/tmp/OpenXML_all_fonts.pkg.30490Lf9KAV"

BTW, I recently had to recover this laptop using time machine after installing Norton Internet Securities which then locked out my ability to use Safari.

I couldn't uninstall it so I simply wiped the HD and used a recent time machine backup just prior to installing Norton.

Any clues as to what is happening?

Do I simply need to re-install OSX 10.5 from the disk and then go thru the updates?

Or

Make a time machine back up, wipe the HD and then re-install the OS from the disk, then drag over my user files?