I have a mid-2009 MacBook Pro with 4 GB of RAM running OS 10.9 Mavericks. My hard drive currently only has about 2 GB of free space on it. Also, my battery is in bad shape. It only gives me about an hour of use on a full charge. Last time I got it to boot-up fully, it happened slowly, and all the programs were crashing, even the Finder (that's what command-option-escape was telling me at least). So I tried to boot into safe mode by holding the shift key down and restarting. It spent 3 minutes trying to start up then suddenly just shut down, as if the battery ran out or power was lost. This was strange since the AC cord was plugged in with a green light on it at the time. I have since tried to start it up again 3 more times, same result each time. MBP tries to boot-up in safe mode for about 3 minutes, then just loses power as if the battery has run out. I'm a bit perplexed by this. What should I do next?