I'm at a loss for use with photo software since my PhotoShop CD appears to be not usable anymore when I needed to reinstall it. :-/
you should be able to approach the publishers of the software for a replacement CD at a nominal cost - the massive cost of the software is for the license to use it, not for the medium it is transferred to you in. As an example, I bought my girlfriend 'The Sims', a popular computer game, but the CD was badly scratched by a dodgy CD drive. We contacted the manufacturer, and received a replacement CD for £7.50 ($12 or so) which just covers the costs of actually sending us a new CD, not the cost of the licence.
Of course, this assumes that you actually hold a licence and you have a version of PhotoShop that is still supported - I'm not sure what will happen if you have an older version.
I'm pretty sure that copyright law allows you to burn a back-up CD for your own use, if you manage to get a replacement it may be worth doing so and storing the original well out of harm's way - as both of us have found out to our cost, CDs are not indestructible!
Hope this helps
Matt
