Merge all sheets from different workbooks into one Workbook
/*
Microsoft Visual Basic for applications window will be displayed,
click Insert > Module, and input the following code into the Module:
*/
Sub GetSheets()
Path = "C:\Users\dt\Desktop\test\"
Filename = Dir(Path & "*.xlsx")
Do While Filename <> ""
Workbooks.Open Filename:=Path & Filename, ReadOnly:=True
For Each Sheet In ActiveWorkbook.Sheets
Sheet.Copy After:=ThisWorkbook.Sheets(1)
Next Sheet
Workbooks(Filename).Close
Filename = Dir()
Loop
End Sub