Reloading windows on older compaq

Hello,

I am trying to reformat my Compag desk top. The restore disk that came with the computer says call Tech support. I called Tech support and they tell me the computer is to old, and the restore disk wont work. They tried to sell me a new computer.
I attempted to load using a restore disk from another old compag. It formated the drive but now it is asking for the security key, which I do not have.

I am completly stuck, becuase no mater what I do the system will not get past this restore disk process. It just keeps asking for that key. I have placed other disks in the drive and restarted the computer, but it keeps telling me to load that restore disk. I tried to create a boot disk from some program on line and same thing. Is there a comand that I can use to force it to start from another disk?

Now that I have this problem I discovered that I have another disk and the key, but I can't get past the first disk to even try and load the other version.

I need help.

Troubled