How in the world do I get 10.5 to work?!

I have Windows 7 64-bit. I know a lot of users are having issues, and some are more lucky than others to find a simple fix. I've been trying every possible fix I've found on various forums from simply uninstalling all Apple software in various orders to downloading and installing the files from the main installer individually to no avail. It's been a month now since I got a new 3GS and have yet to be able to use it, and I'm getting increasingly upset because my old 3G is on the verge of breaking and if it does, I'm without a phone altogether.

Now my problem is the Apple Mobile Device Support, just like a lot of other people. I've specifically tried to repair and reinstall that part of the package multiple times daily since 10.5 unfortunately was put onto my computer. I would really appreciate it if you all could tell me every possible way you know to fix this so I can see if I possibly overlooked a fix somewhere. Thanks in advance.