As dimitar posted, if you did a custom install (clean install) then the program won't be carried over.
If it was an upgrade like I did, the programs did carry forward to Win 7 for me. In one case I had to reinstall the program because it would not load properly.
Here is just a few suggestions, if I understand you correctly:
Have you looked in Program Files folder to see if the directory is still there?
Did you receive a CD with the system that has the program on it to reinstall?
Lastly, go to HP and see if they can provide you a download link to get the prog.