I am unable to print from Office Enterprise 2007.

I have recently upgraded my computer from XP to Windows 7. The Printer is Lexmark P4350.

I have downloaded the Vista driver from Lexmark which works with Windows 7.
However when installing the printer's driver a message comes up saying that
driver is missing and it takes you back to Lexmark's website.

The only way to print from word 2007 is through 'WinWord' - don't know if it
is something to do with administrator setting. But I am the administrator for
the computer.

I have re-installed office and the printer many times and it made no difference

Anyone got any ideas?