We are having a strange problem, if someone changes their printer, it will change the printer on all computers. We have called support, but they ended up breaking our sage 50, so we are hesitant to call again. 

Example - 

Computer A is using printer A as a default

Computer B is using Printer B as a default

Computer C is Using Printer C as a default

If Computer A changes to printer C to print something, B will change to Printer C as well.

Is there any way around this?