Make new Botton ...what software to use ??

Hello all
in my screenset I would like to change the text there is on the botton, I have selected this on Vacuum_down.png and would like to change from "Vacuum" to "ATC-open" do you use paint or other simple software from Windows ???
Eskolin
in my screenset I would like to change the text there is on the botton, I have selected this on Vacuum_down.png and would like to change from "Vacuum" to "ATC-open" do you use paint or other simple software from Windows ???
Eskolin