Date format

Hello,

My excel sheet used to earlier show all dates as d/m/yyyy format by default . Sometime back I installed a software of a video camera after which the default settings have changed to m/d/yyyy pattern.

I have un-installed the software which caused this formatting. But the format continues to remain as m/d/yyyy pattern.

I do not want to select individual cells and change the date pattern each time as it is a big task to select individual cells and change the format. How do i change the settings permanently back to d/m/yyyy pattern for all the excel sheets on my comp.

thanks
sindhu