froze and can't boot..

[N-Y]

So this morning i went to do the update...
mac downloaded the file, asked me to reboot... which i did...
in the reboot process so it can install the new setup everything seemed to freeze, i got a blank white screen and i can see my mouse pointer but it was frozen...
so I held the power button to turn it off, which it did, and i turned it back on...
now my laptop wont boot, i see the apple logo and that little thing under it spinning, it wont go past that...

 

[tinybruk]

Try booting into recovery mode or safe mode. download the combo installer from http://support.apple.com/downloads/#osxlion and install that instead. dont use software update as there seems to be lots of problems with the version on on there

 

[N-Y]

how do i boot into recovery or safe mode?

 

[Sirolway]

Cmd-R during startup (it might be option-R... my memory ...)