Here's some code that creates a snapshot of the current system state, lists all the running programs, and finds their exe paths.

'Module Code
Option Explicit
Public Const TH32CS_SNAPPROCESS As Long = 2&
Public Const MAX_PATH As Integer = 260
Public 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
Public Declare Function CreateToolhelpSnapshot Lib "Kernel32" _
Alias "CreateToolhelp32Snapshot" _
(ByVal lFlags As Long, ByVal lProcessID As Long) As Long

Public Declare Function ProcessFirst Lib "Kernel32" _
Alias "Process32First" _
(ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long

Public Declare Function ProcessNext Lib "Kernel32" _
Alias "Process32Next" _
(ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long

Public Declare Sub CloseHandle Lib "Kernel32" _
(ByVal hPass As Long)

'Form Code
Private Sub Command1_Click()
    Dim hSnapShot As Long
    Dim uProcess As PROCESSENTRY32
    Dim r As Long
    hSnapShot = CreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0&)
    If hSnapShot = 0 Then
        Exit Sub
    End If
    uProcess.dwSize = Len(uProcess)
    r = ProcessFirst(hSnapShot, uProcess)
    Do While r
        List1.AddItem uProcess.szExeFile
        r = ProcessNext(hSnapShot, uProcess)
    Loop
    Call CloseHandle(hSnapShot)
End Sub