ahhh, thank you so much for your reply !!! FINALLY, someone else understands & is aware of the problem I'm having. With all the forums I have put my problem to they either tell me I'm talking rubbish because changing DPI can't affect excel (even when I provide the hard evidence).... or they have no idea and say it must be a problem with my computer.
Just one thing though, I did change my DPI setting to 100% this morning, created a spread sheet similar to the others I had done and emailed it to my daughter. (Her DPI is set to 100% also). When I got to her place I opened the email from her computer and the margins and page breaks were all in the wrong places. So it seems even having DPI set to 100% doesn't alleviate the problem...anyway, i'll do as you suggest and keep it there, seems a sensible thing to do.
YES, I agree this a huge blunder on MS behalf when they DO encourage screen adjustments without any warnings.... crazy!!!!
So seems my years of work have mostly been a waste. I'll have to look around for a similar program to redo it all. Thank you again so much for your reply, now I can stop searching around & adjusting other settings.