When you try to install it on the new machine you will probably
be presented with the following message:  According to our records,
this copy of Microsoft Office XP edition has already been activated
on another computer. If you believe you have received this message
in error, please contact a Customer Support Representative by
clicking OK and following the instructions.

- Click OK when the message appears.
- In the Office Activation Wizard dialog box, select Activate by using
  the telephone, and then click Next.
- Click Next in the Microsoft Office Privacy Policy dialog box.
- In the Activate your product by using the telephone dialog box,
  select your country or region in the list for step 1.
- Dial the phone number that is displayed next to step 2. A customer
  support representative will assist you with activating your copy of
  Office XP.

Information found on Technet:
OFFXP: Cannot Activate OEM Edition More Than Once:
http://support.microsoft.com/default.aspx?scid=kb;en-us;300273

My old computer died.  The funeral is today.  The
software that came with it includes Officexp Pro.  What
will happen when I install my old software on a new
computer as far as activation goes?  Won't it look like I
am running the same software on both computers?