Can't get my CD to load anymore

[gila]

After many years since buying SPWW2, it crashed where i could not get the game to play anymore "not a total computer crash" only WW2.
After deleted it.
I tried to load my CD version,and it would not install,tried everyway i could and nada.

The only thing i can think of is the CD is bad now,or something is wrong with my CD driver,although i load some other CD's and games with no problems.

I could download the free version, but i don't want to lose the CD features,i have really gotten used to them and would not be the same game.

So my question is:

Can one who has already bought the CD,get the the download version at no extra cost?