Half-Life - questions

[lllllllBOB]

Hello all...

Having some Half Life problems.

It Keeps asking for the cd when the cd is in the drive.
Then reads "Could not validate Half-Life"
Is that problem caused by a wrong cd key?
It's the original orange half-life cd,but the cd case is long lost.

I just read that the updates remove the cd check?
* Where can I find updates for Half-Life 1.0.0.5 ?
The links on gamecopyworld are down...
and I didn't see any at the seirra website for that version.

Only need it to play some single player games.
any help would be great.

Thanks,
lllllllBOB