Here is my tool.
It handles transparency through multiple variables so each window can have his own setting. Also displays the transparency level through a tooltip.
Oh and Ctrl+Shift+Wheel up/down does the trick :wink:
#SingleInstance, Force #NoEnv OnExit Exit Menu, Tray, Tip, Transparence Powa! Return ^+WheelDown:: ^+WheelUp:: MouseGetPos, cx, cy, Win_Id WinGetClass, Class, ahk_id %Win_Id% If Class = Progman Return If Needle%Win_Id% = { WinGet, Trans, Transparent, ahk_id %Win_Id% IfEqual, Trans,, SetEnv, Trans, 255 List = %List%%Win_Id%,%Trans% Needle%Win_Id% = %Trans% } IfEqual, A_ThisHotkey, ^+Wheelup, EnvAdd, Needle%Win_Id%, 15 Else Needle%Win_Id% -= 15 IfGreater, Needle%Win_Id%, 255, SetEnv, Needle%Win_Id%, 255 IfLess, Needle%Win_Id%, 30, SetEnv, Needle%Win_Id%, 30 Winset, Transparent,% Needle%Win_Id%, ahk_id %Win_Id% Gosub, Set_ToolTip Return Set_ToolTip: Tooltip,% "Transparency level :" Needle%Win_Id%, % cx+20,% cy+20 SetTimer, RemoveToolTip, 1000 Return RemoveToolTip: SetTimer, RemoveToolTip, Off ToolTip Return Exit: Loop, Parse, List, `, If (A_Index & 1) ; Win_ID's are in odd positions Id = %A_LoopField% Else Winset Transparent, %A_LoopField%, ahk_id %Id% ExitApp