Thanks Waldo for that idea, I will check into it. I still can us a straight edge to guide the saw. There are six windows going in, each one is 38"W X 37"H, that is a lot of hand snipping.
Thanks to all of you guys. I think Waldo's method is going to be the one I use. I have never did this before or watched anyone do it but I am familiar with a circular saw, level, hammer, and square.
If I would have bought the windows the company offers they would not have been double insulated or double hung and would have cost a hundred dollars more a window. The salesman recommended I use these windows, he said they are much nicer than he offers.
I got a all wood construction window, double hung, double insulated, aluminum clad with a screen for $160 a piece tax included direct from the manufacture, but it's my job to install them. The windows are well made and go into expensive homes from what I was told. I looked at them and agree with the salesman they are well made.
I only wish I could have been more articulate. Thanks again Am-O-Tramp