1. Use the following (attach it to ThisWorkbook code)
Private Sub Workbook_Open()
For Each ws In Worksheets
If ws.Name = "Sheet1" Then
ws.Name = "New Name"
End If
Next
End Sub

2. Use
Private Sub Worksheet_Change(ByVal Target As Range)
'Following will run only if there is a change in the range A1:A10
If Not Intersect(Target, Range("A1:A10")) Is Nothing Then
'Your code here...
End If
End Sub

"Som" wrote:

1 . I want to change sheet name automatically by running macro (VB code)

if sheet name = x

then sheet name will be changed to y after openning the file automatically.

can u pls give me the code?

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2.
if i want to trigger a macro on any change in sheet 1, what is the code?