"iPads are quickly becoming a popular and powerful educational tool for classrooms. Beyond the immediate benefit of engaging students, iPads can improve education efficiency and standards. However, many teachers are unsure of how to use them effectively. Coupled with concerns over the costs involved, iPad implementation in schools is seen as an unnecessary and expensive risk. "
"Persistent showing of this progress bar may mean either that there are problems with the system's start-up arguments, or that your system contains errors that it is trying to recover from at start-up.
There are a few things you can try in order to clear this problem, but before attempting to do so be sure your system is fully backed up. If this is happening because of an unrecoverable filesystem error, then you will need to format your drive.
Try clearing PRAM
PRAM stores start-up arguments that are passed to the kernel at boot. Generally these variables are blank, but if there is an error in the PRAM settings then resetting it may help. To reset the PRAM, reboot the system and immediately press the Option-Command-P-R keys after hearing the boot chimes. Hold them and let the system reset a couple of times, and then release them and allow the system to boot normally.
You can also perform a similar operation by manually setting the boot arguments to be blank. To do this, run the following command in the Terminal:
sudo nvram boot-args=""
Check keyboards
One possibility (albeit remote) is that your keyboard could be sending the system the command to boot to Safe Mode. Try starting your system up with the keyboard unplugged to see if it boots normally, and if so then consider replacing your keyboard.
Verify or repair the disk
Boot to an alternative boot volume and use Disk Utility or, more preferably, a dedicated filesystem repair tool like DiskWarrior to run disk verification and repair routines on the boot drive.
Format the drive
If none of the previous options clear the problem, then formatting the drive should be a final step to take to clear the problem. Be sure you have a full and restorable backup of your boot drive, and then both repartition and format the drive using the OS X installation disc. Boot to the disc, choose your language, and choose Disk Utility from the Utilities menu. Then select the drive device (it will be the item above the "Macintosh HD" name-
Enter the following commands in the Terminal application.To disable automated updates:view plainprint?$ defaults write com.google.Keystone.Agent checkInterval 0 $ defaults write com.google.Keystone.Agent checkInterval 0Change the 0 to a 1 to re-enable updates.To set the update frequency:view plainprint?$ defaults write com.google.Keystone.Agent checkInterval <frequency> $ defaults write com.google.Keystone.Agent checkInterval <frequency>
Downloading videos from YouTube is not supported, except for one instance when it is permitted. You can download MP4s of your own uploads, so as long as they do not have any copyrighted content or an audio track added through the Audio tool.
There is a limit of two downloads per hour for downloading your video to MP4. The Download MP4 button will not appear next to your videos if you've already downloaded two videos in an hour