D is not valid win32 application error

There is a joke that goes: "Doctor, it hurts when I do this" "Well, stop doing that". The simple answer, to get rid of the above, don't do whatever cased this.

If you actually want a solution you need to put in a lot more info. When this this come up, from what application, has it always happened? If not, did anything get installed, removed, rebooted, crashed, etc... before the issue came up.