Ciao prova questo:
Dim oLoc
Dim oServ
Dim oObjectSet
Dim oProc
Dim sWQL As String
sWQL = "SELECT * FROM Win32_Process WHERE Name = 'Notepad.exe'"
Set oLoc = CreateObject("WbemScripting.sWbemLocator")
Set oServ = oLoc.ConnectServer(".", "root\cimv2")
Set oObjectSet = oServ.ExecQuery(sWQL)
For Each oProc In oObjectSet
oProc.Terminate
Next
Do While oObjectSet.Count > 0
DoEvents
Loop