i need help my i mac freezes on starup after a few second and if close launcher before that freezes it say error 11 need to save applacation.

What do you do when it freezes? You
should hold down the option key and the
apple key ( side by side) and then press
down the esc key (top left). This is called
force quit. When things look okay again,
be sure to click on special (top), go down
to restart and click on restart. After that
you will have to connect to the internet
again.

Did you just install any new software and
then the problem started? Also you
should try starting while holding the shift
key and this will disable all extensions. If
the computer works fine after disabling
them then it is a extension conflict. If the
problem still exists then it could be a disk
problem. I would start off of the system cd
you got whether it be 9.1 or 8.5 or
whatever. You start off the cd by starting
the computer with the cd in the drive and
hold down the "c" key until you see that
happy little mac face. then you can run
disk first aid and see if it is a disk
problem. there is also a program called
techtool lite. you can check for it at
versiontracker.com . this program can
erase a temporary memory called pram
that sometimes can get corrupted. it can
also rebuild a desktop file to speed
things up and keep it up to date. let me
know if any of this worked or you don't
understand it. hope it helped.
Trev

Start up with the Extensions off. Do this by holding down the Shift key when you are booting up. A message will appear telling you that Extensions are off. If you do not see the error message, then you have an extension conflict. You will have to go into Extensions Manager and turn off unwanted extensions. After turning off a few extensions, reboot and see if the error pops up. If it does, you need to turn off more extensions. If it doesn't, then one of the extensions you turned off was the culprit. BE CAREFUL of which extensions you turn off! If you don't know what it does, then leave it on. Hope this helps.