Why are pointing people to pools instead of helping them for what they ask. I don't see the point
Because sometimes the exact answer to a person's question is not the appropriate answer, especially when there's evidence that the question itself may be based on a flawed premise.
In this case, all the information we have to go on is that there are 12 computers (no information about GPUs, but we can get back to that), and the question being how to get them all to mine - with the assumption being mining Bitcoin, given the forum section it's posted in - as one.
A naive solution would be to simply install the client on each of the computers. Run it on 1, copy the wallet.dat to the other 11, run them all, use 'setgenerate true' or the -gen command line flag, and bob's your uncle.
The down side of that approach is that each of those machines is running as a full node, which is wasteful in space and bandwidth.
So another option is to set up a pool.
You can go for one of the solutions in the thread rapsaodan84 mentioned, or any commonly used pooling software as long as you can set up the environment to run them (which is often a LAMP stack). The down side to that is setting that all up, still having to run at least 1 full node, and managing it. You'll also have to find a CPU(/GPU)-capable miner - the more commonly used these days no longer support CPUs and GPUs; bfgminer still supports it if compiled with support in, but you'd more likely have to check out cpuminer/guiminer or something like that.
A much simpler alternative is to run the mining software of choice and point it to a third party pool or P2Pool. There's plenty to choose from, and the only configuration you typically need is the pool's IP address, port, and a Bitcoin address to which payouts should be sent. Some require additional login information, but even that's relatively simple to set up. Given that there are 0%-fee pools, there isn't any particular reason why you wouldn't use that solution.
But then we get to the part where there's no reason to believe there's anything more than GPUs at play here at best, and only CPUs at worst. In which case, even that last option just means you're going to throw marginal hashing power at it with 12 computers running hot CPUs/GPUs, etc. Now if that's not a problem, that's fine - but then you might as well expend the same energy trying to mine an altcoin and possibly get some returns from it - or fold proteins (FOR SCIENCE!).. or do both. In the case of altcoins, there would be more specific instructions on what miner to use, how to pool together computers on a local network, how to connect to third party pools, etc. often included in instructions for that specific coin.
And so that loops it back around to
your question. To answer the question exactly means to give hydrogone an answer that is ill-advised and ill-fated. By giving the answer we have, they have an answer to the question they most likely meant to be asking. In the rare case that the person asking really did want a straight-up answer to their exact question, there's always the option of saying as much in a reply
tl;dr: If somebody asked me what resistors to choose to drop 12V to 3.3V for an unspecified load, I'd be silly to actually answer their question with resistor figures, or even mentioning zeners, rather than nudging them toward (switch mode) voltage regulators. Unless they needed the answer for homework, in which case it would be even more damaging
