lol tretruhi, what does have creating some fancy themes for windows has to do with security and networking in general? Managing a network in windows aint that hard, a click here and a click there and voila you've got your network running, even withouth the knowledge how those basic things work.

So as i said before and i will keep on repeating that, learn the true basics of networking + security.
So first thing to do is getting a lot of books and start reading.

Now tell me how are you gonna get good at security without any expirience? yes thought so.
So basicly you do this: gain knowledge by reading. Then you're going to put the knowledge you just learned into some testing by setting it up. Then you'll try to work yourself around that (that'll require you to read about commenly tactics used to get into systems.)
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Never argue with fools... They will only drag you down to their level, and beat you with experience...