>It's simple as
>
>LABEL FORM EtiqRv.lbx TO PRINTER PROMPT NOCONSOLE
>
>It work fine for a day and the next day the printer in the prompt screen is the lexmark but the default printer in window is the Dymo .
>
>I have make shure ther is nothing in the tag Fields.

Do you have SET PRINTER TO NAME... elsewhere in your code that may set VFP default printer to the lexmark? Try to issue SET PRINTER TO DEFAULT before LABEL FORM.