Hi all, first i'd like to give you a few pieces of information on what was going on before I restarted my mac. 1. My mac is a 13'' late 2008 mb with 2gb of ram (running leopard). 2. I JUST had my hard drive replaced due to a failure. 3. Before i restarted my computer i was having several "system extenstion" errors and when i tried to repair i recieved the message 'Underlying task reported failure on exit.' At the time, i was also trying to install Adobe CS5 Master Collection trial and i couldn't get past a password screen. This also prompted me to restart. Once the computer began to restart, it began updating boot caches. This was taking a very long time so i walked away from the mb. When i came back i realized the battery had died and when i plugged it back in and tried to get it to boot, it would get to the gray screen with the apple and the spinning logo underneath. But then it simply reboots. I've tried restarting the pram. I've tried rebooting in single user mode (cmd + S) and got to the point where i could rebuild the tree (fsck_hfs -r /dev/disk0s2) and that did it's thing for about ten minutes and it didn't fix the problem. I don't have my install disk but apple is sending me a new one and will be here by friday. Any help?