We have 15 wifi laptop (HP Touchsmart 2, not great at all but not my choice) at one of my schools and they seem to be very hit and miss at the moment when we go to logon to the student desktop, all laptops use the same image some will load the desktop fine, some will time out and need the user to press F5 to refresh the icons and some will just load a temp profile with two icons.

How can I either stop the timing out / need to refresh icons - we have a very capable ruckus network that covers the whole site so I don't believe it's a router / traffic issue
or
get the student icons to load in the temporary profile so that the laptop is still functional for the ICT lesson.

Answers on a postcard please to the usual address :-)