Excel - mass changing hyperlinks

Recording a macro to change the hyperlink in one cell will give you:

Range("E5").Select
Selection.Hyperlinks(1).SubAddress = "Detail!H3"

To change every hyperlink in column E you will need to:

1. Loop through each cell in column E
2. Check if the cell has a hyperlink because trying to change a non-existent hyperlink will throw an error
3. Change the hyperlink to something that can be expressed in a formula based on where the cell is within column E (i.e. its ROW)

Based on your Dummy workbook it seems that hyperlink is to a cell two rows above in column H of the Detail sheet.  The following code limits the loop to the UsedRange because looping through all  1048576 is inefficient.

Sub EditHyperlinks2()
Dim cel As Range
With ThisWorkbook.Sheets("Summary")
   For Each cel In Intersect(.[E:E], .UsedRange)
      If cel.Hyperlinks.Count > 0 Then
         cel.Hyperlinks(1).SubAddress = "Detail!H" & cel.Row - 2
      End If
   Next
End With
End Sub