Macro running so slow

[Hiport]

Hi, the below code is taking forever to run, the worksheet has no formulas, so dont know why its running so slow, i do have 3 other worksheets in the workbook, in which one of those worksheets which does have formulas, should this be the reason?

Is there anything i can do to make it run faster?

Sub Delete_Dupes()
Dim rw1 As Long: rw1 = 1
Dim rwx As Long: rwx = rw1
Dim stepx As Integer
Dim co1 As Integer: co1 = 3
Dim bool As Boolean

Application.ScreenUpdating = False
Do Until Cells(rwx, co1) = ""
    stepx = 1
    If rwx > rw1 Then
        On Error GoTo NewCrit
        bool = IsError(Application.WorksheetFunction.Match(Cells(rwx, co1), Range(Cells(rw1, co1), Cells(rwx - 1, co1)), 0))
        Select Case bool
            Case True
                'no match found thus row = first instance (no delete)
            Case False
                'match found in prior rows therefore duplicate so delete
                Rows(rwx).Delete
                stepx = 0
        End Select
    End If
rwx = rwx + stepx
Loop
Exit Sub
NewCrit:
bool = True
Resume Next
 
Application.ScreenUpdating = True
End Sub

 

[jindon]

Sub Delete_Dupes()
Dim rw1 As Long: rw1 = 1
Dim rwx As Long: rwx = rw1
Dim stepx As Integer
Dim co1 As Integer: co1 = 3
Dim bool As Boolean
 
Application.ScreenUpdating = False
Do Until Cells(rwx, co1) = ""
    stepx = 1
    If rwx > rw1 Then
        On Error GoTo NewCrit
     bool = IsError(Application.WorksheetFunction.Match(Cells(rwx, co1), Range(Cells(rw1, co1), Cells(rwx - 1, co1)), 0))
     Select Case bool
         Case True
             'no match found thus row = first instance (no delete)
         Case False
             'match found in prior rows therefore duplicate so delete
             Rows(rwx).Delete
             stepx = 0
     End Select
    End If
rwx = rwx + stepx
Loop
Exit Sub
NewCrit:
bool = True
Resume Next
 
Application.ScreenUpdating = True
End Sub

The read part doesn't make sense at all.
You can not evaluate the Error value by IsError function resulting from Application.WorksheetFunction.Match, because it raises a RunTime Error when it doesn't find matched value.
If you want to return the error value, you need to use Application.Match instead.
But...
Why you need to use the function ?
try

Sub deldup()
Dim i As Long
Application.ScreenUpdating = False
For i = Cells(Rows.Count).End(xlUp).Row To 2 Step - 1
    If Cells(i - 1, 1).Value = Cells(1, 1).Value Then Rows(i).Delete
Next
End Sub

or

Sub test()
Columns(1).Insert
With Range("b1", Range("b" & Rows.Count).End(xlUp)).Offset(,-1)
    .Formula = "=if(countif(b$1:b1,b1)=1,1,"""")"
    .SpecialCells(-4123,1).EntireRow.Delete
End With
Columns(1).Delete
End Sub