Perhaps it's illegal although I am not sure why.
I am not making any profit by installing it twice
I would understand if it was a business server then different people can use the same software. I am just a home user and I can only use it one at the time.

Anyway my intent was not to do anything illegal I was only trying to see a workaround for those that do not have a cd available and if it can be done
in the first place
As you said "one working operation of xp per license per computer"
So technically if you are trying to do this, the first copy is not working that's why you want to install a second copy,
Now once you fixed the first copy you should delete the second one just to keep things legal