MySQL, Java Connection

It may sound pretty dumb title, but I really faced some difficulties couple of days ago. Here I want to share about the problem I faced while connecting Java with MySQL.
I did tht when I did an "Interfacing" project in 4/1(4th year), but then I didn't face any probs, in fact it is still working in my PC, but one of my best friend Moni was facing a prob while connecting Java with MySQL. I tried a lot to fix the exception "Unexpected end of input stream", but I didn't get the prob bcoz the same code was working in my PC, but it wasn't in Moni's. Then I guessed "Is there any version conflict???"...
That day Moni was in my house with his laptop(HP), I tried & tried, he fell asleep, thn finally I cant fix it & he went to his home.
Then I thought I shud use a fresh PC(or OS) to test the prob, bcoz it was working in my PC, so I tried to solve it in WIN98!!! There is no service in win98, so how will i run MySQL, hmm pretty dumb prob, isn't it??? Then I found that in the bin folder of MySQL, the "mysqld.exe" works as a service, I clicked it & it continued running in background(remember - win98's ctrl+alt+del)!!! then i found tht its not working now...
after tht I googled for couple of hours to fix tht prob, but i was not getting any help, then I typed the "error message"(thts the way to search for a solution of a prob, I didn't know tht) & found the solution in several forums - yes, its a "version conflict". I'm using a driver (i.e. a jar file) for MySQL which is pretty old(3.x) & after 4.x its not backward compatible, they change the protocol of connection. And it was working in my XP bcoz MySQL version in XP was old(3.x), I took it (installed copy) from one of my closest frnd Ruman couple of years ago, as i dont hav installer of tht MySQL,I insatalled latest MySQL in win98, so does Moni, so we are facing tht exception.
So the conclusion is - there exists a version conflict in MySQL driver, Java & never use incompatible versioned driver, tools, api, etc ...
many thanks.