Good afternoon people, please forgive my lack of knowledge/terminology!

I have an Inspiron 1545 and want to change the date format on the BIOS (the thing where you press F2 at start up).

It currently shows that date in the MM/DD/YYYY format and this is affecting one of my programs!  Is there anyway of changing this so that it reads DD/MM/YYYY?  It appears to only let me change the actual date and not the format when I have tried!!

Many thanks

James