You can't.

The first issue is practical: When you install Office, it writes hundreds of
entries in the registry. If you tried to copy the program files to another
computer, you'd be missing the registry entries and the programs wouldn't
work. You need to use the installation CD, not copy.

The second issue is legal: Your license may or may not give you the right
you to use one copy of Office on two computers. There are different
arrangements depending on how you bought Office and/or your computer. Read
the EULA (end user license agreement) to see what's allowed.

--
Regards,
Jay Freedman
Microsoft Word MVP FAQ: http://word.mvps.org