what are you asking for exactly? It seems like you understand what you did... Naw I'll just talk down to you :D
uboa.exe's probability thing activates every minute, rolling a die between 1 and the upper value you put in, namely a 1000. This means he could show up after a thousand minutes, but could take much longer than that. I personally think that's a good value because he'll show up when you least expect it. When you are willing him to appear the surprise is fucking sucked right out, so I deliberately made mine show up almost never and when he does show up it scares the shit out of me.
Actually fuck talking down I have the most amazing story. I was watching Batman animated series on my computer, it was the episode where all the major villains were swapping stories at a game of poker, and "killer croc" was going "So there I was hold up in this quarry when batman came poking around, he was getting closer, CLOSER"
ああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああ
That seriously happened.
That's why you should keep it at 1000.
Anywho, IF YOU DO WANT TO CHANGE THE VALUUUEEE, all you got to do is rename uboa.exe to something else, anything else, and then double-click it again. It will then prompt you to input a new value.
Keep in mind this only works once for any title, so you can't call it uboaa.exe, then go back to uboa.exe and get a result, it has to be a completely new name each time. At least it is on XP.