Office 2007 Student - upgrade demo version & different editions?

[Pheasant Plucker®]

Hi there,

Wishing to purchase Office 2007 Home & Student Edition to install on a
couple of Sony laptops that have the 30-day Demo already installed.

Would it be best to uninstall the demo versions prior to installing the Home
& Student edition or is it OK to just install 'over the top'?

Secondly I see what looks like different versions of Office 2007 Home &
Student Edition;

What is the difference (if any) between Service Desk Edition and just a
plain Home & Student Edition please?

There seems to be a £20 price difference between the two in Staples in the
UK who also have a shelf label that mentions Office 2007 Home & Student
Attach whatever that is?

 

[DL]

Uninstalling any Trial first is a *must*
There is only one Office 2007 H&S from MS
Service Desk Edition is one that is pre packaged by MS for certain
retailers, it may contain other software, you'll have to read the label

H&S is £84.99 on Staples online store, its £69.97 on Amazon - your call