Help with cd key

So, i lost a cd key and i thought i'd search one on the net.
Now, when i enter a net cd key for any game or anything (even if i HAVE the cd, just to try) they say its invalid.
Ofcourse its invalid, but that error shouldn't come, thats why they post the key.

Now what ?_?

Some programs can be key specfic, or can only used keys that have never been used before, did you try to look for a keygen for your program?

yup and its not one program, all of em ;-; (without the key lol)

Could you list the programs for me, I will do some searching for a solution if you wish. Also you can send me them in a PM to keep it private.

Lets choose HL Anthology, cuz i finally figured how steam works ;-;

need to activate product lol