I noticed that both the Customer Number and Request Number are in Sheet1 in Cells(4, 2) = B4 and in Cells(2, 5) = E2
If you change that, you need to change these references also.
Code:
Sub Maybe()
Dim wb1 As Workbook, wbName As String, j As Long
Application.ScreenUpdating = False
Set wb1 = ThisWorkbook
wbName = wb1.Sheets("Sheet1").Cells(4, 2).Value & " " & wb1.Sheets("Sheet1").Cells(2, 5).Value
ActiveWorkbook.SaveAs Filename:=CreateObject("WScript.Shell").Specialfolders("Desktop") & "\" & wbName, _
FileFormat:=xlOpenXMLWorkbookMacroEnabled
ActiveWorkbook.Close
Application.ScreenUpdating = True
End Sub