C# Signature:

[DllImport("advapi32.dll", SetLastError=true)]
static extern TODO CreateService(TODO);

VB Signature:

    <DllImport("advapi32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function CreateService(ByVal hSCManager As IntPtr, ByVal serviceName As String, _
                ByVal displayName As String, ByVal desiredAccess As Int32, ByVal serviceType As Int32, _
                ByVal startType As Int32, ByVal errorcontrol As Int32, ByVal binaryPathName As String, _
                ByVal loadOrderGroup As String, ByVal TagBY As Int32, ByVal dependencides As String, _
                ByVal serviceStartName As String, ByVal password As String) As IntPtr

User-Defined Types:

None.

Notes:

The 4th parameter from the end, TagBY, should - accordig to the API documention, be a ByRef parameter. Unfortunatly, the call only works if the parameter is ByVal.

Tips & Tricks:

Please add some!

Sample Code:

Dim scHandle As IntPtr = OpenSCManager(Nothing, Nothing, SC_MANAGER_ALL_ACCESS)
    Dim serviceName As String = "AAATestService"
    Dim displayName As String = "AAATestDisplayName"

    If OpenFileDialog1.ShowDialog() <> DialogResult.OK Then
        MsgBox("aborting")
    End If

    Dim pathName As String = Chr(34) & OpenFileDialog1.FileName & Chr(34)

    Dim serviceHandle As IntPtr = CreateService(scHandle, serviceName, displayName, SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, _
                SERVICE_AUTO_START, SERVICE_ERROR_NORMAL, pathName, Nothing, 0, Nothing, Nothing, Nothing)
    If serviceHandle.Equals(IntPtr.Zero) Then
        MsgBox(Marshal.GetLastWin32Error())
    End If

    CloseServiceHandle(serviceHandle)
    CloseHandle(scHandle)

Alternative Managed API:

System.ServiceProcess.ServiceInstaller - http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemServiceProcessServiceInstallerClassTopic.asp