This is a freeware so no need to worry about expenses plus it is light and has neat features in it like the mouse over transparency function.
It works on the different Operating systems listed above so you do not have to problem with compatibility. I haven't tried it in windows 7 so I do not have a clue yet whether itwould and it did worked. So I might as well share you this tool to you. Enjoy and hope you will like it!