Hi,
my problem is how I can create this adress like you ("http://lalescu.ro/liviu/fet/forum/index.php?board=1.0)
me I want have an adress for check
Well, the address you mentioned ( http://lalescu.ro/liviu/fet/forum/index.php?board=1.0 ) was/is done in more steps:
1) I registered my domain name "lalescu.ro" on the Romanian top level list: http://rotld.ro/ . I paid ~40 euros for lifetime, but this is only for Romania (.ro domains).
2) I hosted my domain on a paid server. In the past I used others; since ~4 years I am using http://hostgator.com/ and I am extremely satisfied with them. I pay ~10$ per month (this is the second least expensive hosting plan, and I can host unlimited domains with this price). I get virtually unlimited traffic and storage, and a very good traffic speed.
3) I installed the free SMF forum ( http://www.simplemachines.org/ )
I think there are also free services (with lower quality and probably with annoying commercials), but I cannot recommend one. You may search on the internet.
Hmm, maybe your question was simpler. You could use your own computer as a server, but I am not sure how to do this. Maybe use your IP, or something with localhost.