Mike, I think you are asking if you can install (not download) Microsoft Streets and Trips 2008 more than twice. You can "activate" your software installation on up two computers. In your case, if you are considering to reinstall Streets & Trips on the same computer, the activation process should recognize you are activating the program on the same laptop (unless hardware was added or changed), and it should let you activate again (and again ).
The error message you received sometimes just indicates your GPS receiver cannot see sufficient number of satellites yet. It could be you are testing indoor(?), or the GPS receiver just needs longer time to acquire satellite fix (bring it outdoor, and give it even up to 20 minutes, and then try to start Streets & Trips).