You can download the install files for Creative Suite 5 by following the directions listed at http://prodesigntools.com/all-adobe-cs5-direct-download-links.html. I would recommend making a back up of the files in case you need them again in the future.
I am looking for something very similar.. I just got a new computer and I have the student teacher edition of photoshop (5) and Lightroom 3 - Can you also advise for me? Thanks!
You can follow the page linked at http://forums.adobe.com/thread/981369 to find downloads of older versions of Adobe software. Click on the download tab at the top of the page to see a list and directions on how to download the older versions.