applesoftwareupdate.msi missing

I've been trying to update iTunes and it didn't work for some reason so i uninstalled it and tried to reinstall it the same message always pop up it says that an error occurred on the windows installer package. So i checked on forums and found out that i might need to uninstall apple software update but every time i try that another message pop saying that the applesoftwareupdate.msi file was not found anyone can help me on where can i find this file.

Windows 7

thanks in advance