Cannot Close Excel

[huyhk]

My code is

Public xApp As Excel.Application
Private Sub Command1_Click()
    Dim wb As New Excel.Workbook, str As String
    Set xApp = CreateObject("Excel.Application")    
    xApp.Visible = True
    str = "Myfile.xls"
    Set wb = xApp.Workbooks.Open(FileName:=str)
    
    wb.Close False
End Sub

Private Sub Command2_Click()
    xApp.Quit
    Set xApp = Nothing
End Sub

When I click on Command2, Excel window is closed but an Excel process always appears in Window Task Manager,Process Tab. If I run above code again, two Excel processes are in Window Task Manager and so on.
Anyone can help me to terminate Excel processes?

[Edneeis]

Try setting wb to nothing also:

Public xApp As Excel.Application
Private Sub Command1_Click()
    Dim wb As New Excel.Workbook, str As String
    Set xApp = CreateObject("Excel.Application")    
    xApp.Visible = True
    str = "Myfile.xls"
    Set wb = xApp.Workbooks.Open(FileName:=str)
    
    wb.Close False
'set this to nothing also
    set wb=nothing
End Sub
 
Private Sub Command2_Click()
    xApp.Quit
    Set xApp = Nothing
End Sub

[SoftwareMaker]

The most common problem many users faced....

Use
Dim xls as excelobject
then
Set xls = new excelobject

If you use
Dim xls as NEW excelobject, you are telling VB to get xls ready for a new instance whenever you call it again after you destroy the first instance.

Therefore if you use this :
Dim myobject as NEW object
myobject.Color = "Red"
set myobject = nothing
myobject.Color = "Blue"

Myobject will be automatically created as a new object without you having to use the set statement...

Therefore, your problem is :
Instead of
Dim wb As New Excel.Workbook, str As String
Use this
Dim wb as Excel.Workbook

[huyhk]

Hey, I found the problem. The Excel file is too large. IF I open a medium Excel file, error doesnot occur

[Patoooey]

Never use Dim As New.....causes too many problems.

Dim MyXL As Excel.Application
    
    On Error Resume Next
 
    ' see if it's open already
    Set MyXL = GetObject(, "Excel.Application")
 
    If Err.Number <> 0 Then
        ' if not...open it
        Set MyXL = CreateObject("Excel.Application")
    End If
 
    Err.Clear
 
    On Error GoTo 0
 
    MyXL.Quit
    Set MyXL = Nothing