Getting spammed, help

Im running heavy modified, integrated forum version 7.01.
so i cant update.

i like the forum i have just fine ;)
But now lately we are getting spammed by post spammers.

if there a way for me to block those spammers ?
ive tried to block there ip, but it dos not help, thy can spamm anyway, still whit same ip :(

i tried to incorporate the CAPTCH thing.
But its to hard for me, cant get it to work, in forum, can some one help me ?

Yes you are right :( but the thing is, its much much, modified. and integrated, in to my site.

And over the years, more that 3 programmers have worked on it, so I don’t even know all the things that has been don to it.

But I guess I must, do an upgrade :(

.

There are some Questions I need to ask you then.

Can I upgrade from 7 til 8, Database only, and still run V7 on 8 database.

(the reason is, then I can slowly update one part at a time of the forum, and hopefully get it to work whit my site, 1 thing at a time), and put old files back if problems, I cant fix happens, and need expert programmer help to solve those problems.

Do you know if its now in version 8 possible to have more then 1 language?

So that users can choose what language thy want in the forum?

And when i upgrade from 7 to 8, is there some things I have to be aware of?