Mac or Windows? Which OS? It might not be necessary to reinstall. Be sure you follow a few simple troubleshooting steps - restart Finale, restart computer, reset the preferences.

If you do want to reinstall, be sure to unauthorize the software first (Help Menu). You've purchased the software, so log in to your account and download just as you did the first time.

Along the same lines as what Bruce mentioned, just curious why you're thinking about reinstalling Finale? There is certainly no problem with wanting to reinstall, just curious for some more details about the issue before jumping to that troubleshooting option? There may be an easier way.

Please let us know!

our computer had crashed and everuthing needs to be reinstalled on the same computer.  I need help doing this please

So just do it, as the Nike commercial says.

1. Go to the My Account tab at the http://finalemusic.com web site. (You dd register your copy of Final, I expect.)
2. Download the appropriate installer from there. (You didn't say which version of Finale or Operating System you use.)
3. Use the "Submit a request" link above on this page to contact MakeMusic to restore the authorization lost in your computer crash.