We have many laptops, not many desktops. School stuff is all Dell.
The laptops are D830 or D530 which have the most problems. Switching to Linux is not an option.
Most students come with their own new laptops, Moodle works OK on these laptops. But students don't press the 'turn edit on' button.
As far as I can see now, it's the 3-4 year old PC's running Windows XP and IE8 that are unable to edit courses. If we install Google Chrome they work better, but still not perfect.
If we take a D830 laptop and we install Windows 8 and IE 10 on it, it runs far better.
However, Moodle is not the only thing we run. That's why Windows 8 and Linux are not yet options. An upgrade to Windows 7 would help, but we have about 5-6 schools and about 300-400 computers. It's not an easy task. Also the tech guys are not so happy if Moodle pushes them to Windows 7 without further testing what the consequences will be for all other educational software they are running on these machines.