Welcome to the forum.
You should be able to go to Adobe.com, then sign in with your Adobe ID, and go to your account, where all Registered products, or products that you purchased directly from Adobe, should be available. If you purchased a download, the link to that should be available too. If you have any issues, you can do a Live Chat with an Adobe Customer Support rep., and get that link and your S/N, if necessary. Do have your invoice handy, as it might be asked for.
I would also make a copy of the installers and all files on DVD, and note your S/N on the disc, and the case.
How did you install it originally...
a. from installation files from online purchase download
b. from installation disc from boxed product
This is my understanding...if installation files from online purchase within a given period of time (not sure how many years), you should be able to get help from Adobe
If not and installation disc is involved, you will not get a Premiere Elements 8 download from Adobe at this date. A popular online vender may have a copy for sale (new serial number).
An Adobe decision, just my speculation.