Can't install D2 with license key

I have a new computer and am trying to install Diablo 2. I keep getting error message when I try to enter the “CD” key during installation. Is the license key (which I have) the same as a CD key? I’ve tried several times to use the D2 license key and the LOD license key; neither works.
Help is appreciated.

Greetings,

If you bought a retail (actual CD) with a CD key in the box, if the condition is “used” the chances are that the key is redeemed by the previous owner or so.
If it’s new, which is actually rare and quite expensive, which I don’t think so then I have no idea and you should contact support.
At any case, games that are demanding redeem codes are very risky to buy if they’re used.
Now, the best thing you can do from now on, is to buy the game from the original - official website or app (battle.net). If you did buy those keys in-here, check your games and subscriptions if a download is available, if not, that means that your account is probably compromised and you need to change password in bnet, email and then unfortunately buy again.
Contact support before doing so, maybe things changed (which I hardly believe).

Whatever happens, good luck.

As an addition to what Lupinian mentioned, if this is a physical key that is 16-digits, please claim it on the Blizzard account. Once the 16-digit key is claimed, the new 26-digit key to use will be under the Account Games & Subscription section near the bottom of the page.

If all else fails, try reinstalling the game, especially for the invalid CD Key error. Otherwise, please contact our customer support team to look into this further!