The following code shows how you can kill a process using vb6 code. 

Example

Private Sub cmdKill_Click()
‘ Usage:
Dim pID As Long
Dim i As Integer
Dim strExe As String
strExe = “calc.Exe”
For i = 0 To 4
pID = Shell(strExe, vbNormalFocus)
Next i
‘Five instances of notpade.exe is now created
Debug.Assert False
MsgBox “It is ” & _
KillApp(strExe) & _
” that all instances of ” & vbCrLf & _
strExe & _
” have been terminated!”
End Sub

Declaration

Option Explicit
Const MAX_PATH& = 260

Declare Function TerminateProcess _
Lib “kernel32″ (ByVal ApphProcess As Long, _
ByVal uExitCode As Long) As Long
Declare Function OpenProcess Lib _
“kernel32″ (ByVal dwDesiredAccess As Long, _
ByVal blnheritHandle As Long, _
ByVal dwAppProcessId As Long) As Long
Declare Function ProcessFirst _
Lib “kernel32″ Alias “Process32First” _
(ByVal hSnapshot As Long, _
uProcess As PROCESSENTRY32) As Long
Declare Function ProcessNext _
Lib “kernel32″ Alias “Process32Next” _
(ByVal hSnapshot As Long, _
uProcess As PROCESSENTRY32) As Long
Declare Function CreateToolhelpSnapshot _
Lib “kernel32″ Alias “CreateToolhelp32Snapshot” _
(ByVal lFlags As Long, _
lProcessID As Long) As Long
Declare Function CloseHandle _
Lib “kernel32″ (ByVal hObject As Long) As Long

Private Type LUID
lowpart As Long
highpart As Long
End Type

Private Type TOKEN_PRIVILEGES
PrivilegeCount As Long
LuidUDT As LUID
Attributes As Long
End Type

Const TOKEN_ADJUST_PRIVILEGES = &H20
Const TOKEN_QUERY = &H8
Const SE_PRIVILEGE_ENABLED = &H2
Const PROCESS_ALL_ACCESS = &H1F0FFF

Private Declare Function GetVersion _
Lib “kernel32″ () As Long
Private Declare Function GetCurrentProcess _
Lib “kernel32″ () As Long
Private Declare Function OpenProcessToken _
Lib “advapi32″ (ByVal ProcessHandle As Long, _
ByVal DesiredAccess As Long, _
TokenHandle As Long) As Long
Private Declare Function LookupPrivilegeValue _
Lib “advapi32″ Alias “LookupPrivilegeValueA” _
(ByVal lpSystemName As String, _
ByVal lpName As String, _
lpLuid As LUID) As Long
Private Declare Function AdjustTokenPrivileges _
Lib “advapi32″ (ByVal TokenHandle As Long, _
ByVal DisableAllPrivileges As Long, _
NewState As TOKEN_PRIVILEGES, _
ByVal BufferLength As Long, _
PreviousState As Any, _
ReturnLength As Any) As Long

Type PROCESSENTRY32
dwSize As Long
cntUsage As Long
th32ProcessID As Long
th32DefaultHeapID As Long
th32ModuleID As Long
cntThreads As Long
th32ParentProcessID As Long
pcPriClassBase As Long
dwFlags As Long
szexeFile As String * MAX_PATH
End Type

Functions

Public Function KillApp(myName As String) As Boolean
Const TH32CS_SNAPPROCESS As Long = 2&
Const PROCESS_ALL_ACCESS = 0
Dim uProcess As PROCESSENTRY32
Dim rProcessFound As Long
Dim hSnapshot As Long
Dim szExename As String
Dim exitCode As Long
Dim myProcess As Long
Dim AppKill As Boolean
Dim appCount As Integer
Dim i As Integer
On Local Error GoTo Finish
appCount = 0

uProcess.dwSize = Len(uProcess)
hSnapshot = CreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0&)

rProcessFound = ProcessFirst(hSnapshot, uProcess)
Do While rProcessFound
i = InStr(1, uProcess.szexeFile, Chr(0))
szExename = LCase$(Left$(uProcess.szexeFile, i - 1))
If Right$(szExename, Len(myName)) = LCase$(myName) Then
KillApp = True
appCount = appCount + 1
myProcess = OpenProcess(PROCESS_ALL_ACCESS, False, uProcess.th32ProcessID)
If KillProcess(uProcess.th32ProcessID, 0) Then
‘For debug…. Remove this
MsgBox “Instance no. ” & appCount & ” of ” & szExename & ” was terminated!”
End If
End If
rProcessFound = ProcessNext(hSnapshot, uProcess)
Loop
Call CloseHandle(hSnapshot)
Exit Function
Finish:
MsgBox “Error!”
End Function
‘Terminate any application and return an exit code to Windows.
Function KillProcess(ByVal hProcessID As Long, Optional ByVal exitCode As Long) As Boolean
Dim hToken As Long
Dim hProcess As Long
Dim tp As TOKEN_PRIVILEGESIf GetVersion() >= 0 ThenIf OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES Or TOKEN_QUERY, hToken) = 0 Then
GoTo CleanUp
End If 

If LookupPrivilegeValue(”", “SeDebugPrivilege”, tp.LuidUDT) = 0 Then
GoTo CleanUp
End If

tp.PrivilegeCount = 1
tp.Attributes = SE_PRIVILEGE_ENABLED

If AdjustTokenPrivileges(hToken, False, tp, 0, ByVal 0&, ByVal 0&) = 0 Then
GoTo CleanUp
End If
End If

hProcess = OpenProcess(PROCESS_ALL_ACCESS, 0, hProcessID)
If hProcess Then

KillProcess = (TerminateProcess(hProcess, exitCode) <> 0)
‘ close the process handle
CloseHandle hProcess
End If

If GetVersion() >= 0 Then
‘ under NT restore original privileges
tp.Attributes = 0
AdjustTokenPrivileges hToken, False, tp, 0, ByVal 0&, ByVal 0&

CleanUp:
If hToken Then CloseHandle hToken
End If
End Function