Leappad problems My leappad ultra did an update when we tuned it on, after the update was complete it went to a screen that said restart now and once we restarted it it cut off and now when we turn it back on it keeps going to the same page that says installation complete restart now and won't go past that page

SOURCE: xbox 360 update problems

If the above suggestion does not work, which i think should, try to delete cache on Xbox 360 console. Firstly, go to System tab, then go to Memory, then, highlight HDD (DONT CLICK) and press Y. Enter x, x, left bumper, right bumper, x and x . Sorry, but this does not always work, if it dows, when the tab appears that asks if you want to perform maintenance, click yes

SOURCE: wont start up completly

there is the single user start-up, which you were thinking of. There is also a safe-boot for macs.

To start up into Safe Mode (to Safe Boot), do this:

1. Be sure the computer is shut down.
2. Press the power button.
3. Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone but not before.
4. Release the Shift key when you see the gray Apple icon and the progress indicator (looks like a spinning gear).

During startup in Mac OS X 10.4 or later, you will see "Safe Boot" on the login window, which appears even if you normally log in automatically.

During startup in Mac OS X 10.2 through 10.3.9, you will see "Safe Boot" on the Mac OS X startup screen.

To leave Safe Mode in any version of Mac OS X, restart the computer normally, without holding any keys during startup.

SOURCE: can't install mac osx 10.5.7 combo update on 10.5.2

The 10.5.7 update sometimes does several automatic restarts - depending on the mac and the previously installed OS version.
In my opinion the 10.5.7 update has been the strangest I have done.
Try this.
Hold down the power button for about 10 seconds. The MacBook should now be off - but it may restart automatically while flashing the sleep light at you - and make a long beep noise. Don't worry if that happens just let it do whatever it does. Watch the screen and follow any prompts that come up.
If the MacBook did not turn itself back on, hold the power button down again for about 10 seconds. What happens now?
Don't press any other buttons unless the computer tells you to.
If however, you end up with another 3 hour wait then something is definitely wrong and you need to take it in to a specialist.

SOURCE: keeps restarting

I do not know about the screeching part, that could be part of the problem or completely independent of the problem. When my machine kept repeating the "startup" process, it was because my bulbs went out. The printer then would never get warm enough to melt the ink to begin printing, so it would just keep restarting, and restarting the warming up process. One way to tell is to take off the side cover. Then peer into the side and see if you see a bright light - which would be your bulbs. I have no idea though what to tell you about the screeching thing.

SOURCE: An update was done but when I tried to restart my

Reboot the computer and try again. If the problem continues, go to the Mozilla website and locate the update issues for your version. I recommend using Google Chrome than Firefox.