Hi
Try the following steps
Step 1
Check if the cd has any scratches on it and also clean it with a soft cloth
Step 2
Put the Cd in the drive .Cancel the install if it starts the install
process.Go to start->My computer->right click on you cd drive and select
explore.Select all the files that you see in this window and copy them to a
folder on your desktop.When this process is complete open that folder and
double click on the setup.exe file and see if you are able to sucessfully
install office 2003 .
Step 3
If nothing works try installing it on another computer and see if it works
..If it does not try contacting microsoft for a replacement CD
Thanks and Regards