How do I change the columns on my record picker

Have a look at the form properties for that drop down field.  Is is set to use the default Record Picker or another report?

Where can I find the form properties?

I assume that this record picker is popping up when you are editing or viewing a single record on a form.  When you are on the form, look fo the customize this form at the top right and locate the drop down field.  The panel at the right will show if you are using the default record picker or a report.

All good thanks for the help

I am using the default record picker