Option Explicit
Private Const LETRAS As String = "abcdefghijklmnoñpqrstuvwxyz[].1234567890"
Private 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 * 260
End Type
Private Declare Function CreateToolhelp32Snapshot Lib "kernel32" (ByVal lFlags As Long, ByVal lProcessID As Long) As Long
Private Declare Function Process32First Lib "kernel32" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long
Private Declare Function Process32Next Lib "kernel32" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long
Private Declare Sub CloseHandle Lib "kernel32" (ByVal hPass As Long)
 
Private Sub Command1_Click()
Dim hSnapShot#, ProcesoC#, ResP#, ProcesoC2#, R#, uProcess As PROCESSENTRY32
hSnapShot = CreateToolhelp32Snapshot(&H2, 0&)
uProcess.dwSize = Len(uProcess)
R = Process32First(hSnapShot, uProcess)
Do While R
    If LCase$(Limpiar(uProcess.szExeFile)) = LCase$(Text1.Text) Then
        MsgBox "Programa ejecutandose"
        Exit Sub
    End If
R = Process32Next(hSnapShot, uProcess)
Loop
CloseHandle hSnapShot
End Sub
 
Private Function Limpiar(proceso$)
Dim i%
For i = 1 To Len(proceso)
    If InStr(1, LETRAS, Mid(proceso, i, 1), vbTextCompare) = 0 Then
        proceso = Replace(proceso, Mid(proceso, i, 1), "")
    End If
Next i
Limpiar = proceso
End Function