Trying to identify this Operator. No idea brand of Windows

Thanks for writing in! Take a look at the 39-257B which has a housing similar to yours, but it has two mounting holes top and bottom. Take a look at the 39-025 operator. I wonder if an operator like this one or any others from the web site would be a better replacement to yours. However, make sure the mounting holes at the top and bottom match yours. Take note you might need to cut off that side leg on the housing if it gets in the way on your window.