MS Word Student 2007 opening attachment file problem

Hi,

Using winXP. Installed a copy of MS Office Home & Student 2007 bought at staples.

As I attempt to download a word file (attached to an email that was sent to me) I run into problems.

When I click on the attachment then the "Windows Installer" window pops up and says "Preparing to Install"

Then a MS Office Standard Edition 2003 window pops up:
Installation error: file not found.
A required installation file sku112.cab could not be found

How do I get this corrected? why is the ms office 2003 trying to work when I use ms office 2007?please rply......