You are only assigning your SQL to a string; you are not executing anything:
Code:
strSQL = "UPDATE [Andrews HWST] SET [Andrews HWST].andrews_date_datalable = " & Now() & " WHERE ((([Andrews HWST].andrews_date_datalable) Is Null ));"
Debug.Print strSQL
MsgBox "File created and records date stamped"
Try this, adding the #s:
Code:
DoCmd.RunSQL "UPDATE [Andrews HWST] SET [Andrews HWST].andrews_date_datalable = #" & Now() & "# WHERE ((([Andrews HWST].andrews_date_datalable) Is Null ));"
MsgBox "File created and records date stamped"