You can't run a program using the Program Files from another computer. It doesn't work that way. There is more to your programs than just those Program Files you can see. There is a lot of registry stuff, as well. Just copying the Program Files over does not install it on the netbook (or any other computer, for that matter). You must actually go through the installation.
Assuming you have a legal Microsoft Office disc, a valid product key, and no USB external optical drive, here is how to install programs in general (from a CD or DVD) on a netbook:
On a computer that has an optical drive, download and install ImgBurn
. With the Office installation disc in the optical drive, "Create image file from disc" using ImgBurn.
Now, on the netbook...download and install Virtual Clone Drive
. Using a flash drive or similar means of transfer, copy the ISO file you made using ImgBurn from the computer it was made on to the netbook (computer to flash drive, flash drive to netbook). Mount the ISO file using Virtual Clone Drive on the netbook.
You should now be able to install Office on the netbook as if you had the physical installation disc in a drive (or any other program that requires the use of an optical drive).
If you don't have a disc for Office, you still have a few choices. You can download and install the Office 2010 Beta
, use Open Office
(I don't like it, personally), or go buy a 2007 or 2003 Office disc.