Try to do something like this:
Open a command prompt window (cmd) as an administrator
Go to AutoItX directory (default on Windows 7 : cd C:\Program Files (x86)\AutoIt3\AutoItX\)
Type these two commands :
regsvr32.exe AutoItX3.dll
regsvr32.exe AutoItX3_x64.dll
Then, try so:
import win32com.client
autoit = win32com.client.Dispatch("AutoItX3.Control")
#Run(program, workingdir, show_flag)
autoit.Run("notepad.exe",'',5)
Description of the parameters for the function Run
you can find here. Integer values for parameter show_flag
you can find here (5 corresponds SW_SHOW
)