Forum Moderators: travelin cat
If the HD is not too full and something went wrong with the updates, you could do an "Archive and Install" with the CD that came with it and try the updates again...
What screen do you see when it attempts to boot up? Do you have anything else attached via USB or FireWire (besides the keyboard and mouse)? If so, disconnect those before trying any of the above.
Hope this helps & good luck!
I had to do this last weekend after my Cube got fried by a power surge. Thankfully disc utility brought back my my iTunes Library.