Can't init error

Guys I have just done a fresh install of FSX and I thought all was going well but I've installed FSX SDK SP1a and then 2 and I'm getting 'Simconnect Can't init error' on starting FSX. I notice that SP1a refuses to install anywhere except Programfiles x86 folder, even when I direct it elsewhere. Yet in control panel the SP2 seems to be installed on a different drive in my new FSX folder. However, there is no option in the installation to change the directory of the SP2 installation. Also in winsxs there are files from 2012 (which may have been the first time i installed the sdk on my computer) AND from the latest installation. But I can't delete the old ones because of the UTTERLY STUPID permissions thing on Windows that causes so many problems grrrr!

What can I do? Should both SDK service packs be in the same folder or would that not matter? How do I get this working again? I never had this problem before so it's obviously to do with the new install.