Q: missing dll? not detecting devices or accessing iTunes store

When I try to reinstall or update I am told I am missing a required DLL

Although you're getting a different error message, try the procedure from the following user tip with that one:

"The administrator has set policies to prevent this installation" error messages when installing iTunes for Windows on Windows Vista and Windows 7 systems

but I still cannot connect to the itunes store

Is iTunes endlessly saying "Accessing iTunes Store"? Or is something a bit different going on?

Many thanks.

With those symptoms, I'd try the following document:

Apple software on Windows: May see performance issues and blank iTunes Store

(If there's a SpeedBit LSP showing up in Autoruns, it's usually best to just uninstall your SpeedBit Video Accelerator.)

You're welcome. Glad you got things sorted out.