copy entire row to new worksheet if column 2 = "X"

Try this code

Option Explicit

Sub copy_sheet()
Dim i As Long, lrow As Long
Dim sname As String

Application.ScreenUpdating = False

With Worksheets("Sheet1")
    lrow = .Range("A" & .Rows.Count).End(xlUp).Row
    For i = 2 To lrow
        sname = .Range("B" & i).Value
        If Not Evaluate("ISREF('" & sname & "'!A1)") Then
            Worksheets.Add(After:=Worksheets(Worksheets.Count)).Name = sname
            .Rows("1:1").Copy Worksheets(sname).Range("A1")
        End If
        .Rows(i).Copy Worksheets(sname).Range("A" & Rows.Count).End(xlUp).Offset(1, 0)
    Next i
End With

MsgBox "Data transfer complete"

Application.ScreenUpdating = True

End Sub

Copy the Excel VBA code
Select the workbook in which you want to store the Excel VBA code
Hold the Alt key, and press the F11 key, to open the Visual Basic Editor
Choose Insert | Module
Where the cursor is flashing, choose Edit | Paste

To run the Excel VBA code:
Choose Tools | Macro | Macros
Select a macro in the list, and click the Run button