Searching for Printer Driver ?? Help??

I am trying to find a driver for my printer at the office and can not seem to find anything. If in fact a driver is what I need.

This is my problem: I can print to from my computer but it will only print 8.5x11 paper, I can not get it to change to 11x14 or 11x17. It previews at the right size but it prints on the 8.5x11.

Can this be solved in the properties of the printer or should I try something else.

Thanks to all

 

Sorry I bet a model number might help if you know what I mean

Its a Sharp AR287

 

Well, you can download the latest driver here (pick software). And you can also download the latest manual to see if the machine supports other paper sizes and how to configure that.