help me in seeing the source code of th software

LOL, wouldn't we all love to do that then we would not need to buy software any more. Wait that is open source. ;) There are some decompilers our there that try their best to change the Machine Language (Assembly) into a programming language. First you have to decide what language you want to use. I recommend C because it is the closest to Assembly there is. Also be aware the formatting will be messed up it will use spaghetti loops on (for get about inheritance) and there will be no code documentation. Also the variables will be alphabet soup. So good luck with that and don't forget, it is against the law.

It depends. If it's a Java application, it can usually be turned back into readable Java source code, complete with original class, variable and method names. If it's in C or C++, you'd be better off finding an equivalent Open Source application (if yours is not already Open Source) and downloading the source from the repository. You didn't say which executable exactly you are referring to. So we can only reply in the most general terms.