I am using fOSUserName to get the User ID from the registry. I need to use this as a
default in a Combo/List box. It shows on the form but does not update the table the form is based on. This has become a Quest and I'm lost.

Place a hidden txbox on your form with it's control source set to the table and field you want the info to go to. Then you will need to use some event within the form to copy the value you recieved from the Function to the hidden txtbox. This will pass the value to the table you wish. You could maybe use the On Current event of the form to do this transfer, but this depends on your situation.

HTH
RDH