What should I do next to assure my hard drive is OK?

Question

Hi everyone
I have a Macbook Version 10.6.8
So as I was working on an essay last night, my computer began to freeze (especially when I would launch a browser such as firefox or chrome).  Pressed for time, I tried restarting my computer multiple times, at which my computer continued to freeze (Finder was not responding?).  So I decided to Safe Boot. 
At this point, the freezing stopped, and I was able to continue working on my essay (cool).  I thought everything was fine, so once I reached a point where I had to go to sleep, I saved my work and told my computer to restart, just to see if problems would continue to happen afterwards. 
At this point, when I booted up my macbook, a gray loading bar would appear at the initial loading screen with a white background and the apple logo.  The gray bar would load only about 1/8 of the way, then after a while it would disappear, and re-appear, again loading about 1/8. But this time, after a while, my laptop would simply shut off.  I tried restarting my computer many times, but the same thing would happen. 
Eventually I did some research and found that this was mainly a hard drive issue.  My hard drive would sometimes make a noise as the startup loaded, usually when the gray bar stopped loading. 
After having a friend take a look at it, who miraculously fixed it (I don't know what he did), my laptop is now functioning normally.  I backed up my files, and checked disk utility, which said that my harddrive was "OK". 
Should I take my laptop to the genius bar just to make sure?  Also, am I still technically in safe boot?  I'm afraid that if I turn my laptop off and restart it, the same problem will occur and I will have to replace my hard drive.  What should I do at this point?
Thanks!

Answer 1

Download Smart Utility from http://www.volitans-software.com/smart_utility.php which will give you a readout on your SMART sensors as well as a health assessment on the drive.
If you run Disk Utility verify hard disk and it says everything is OK, and SMART Utility says everything is OK, there's not much else anyone can do. You could run the Apple Hardware Test which would test your hard drive as well as the rest of your hardware (if you do that, run the extended test).  Ensure you have 10%+ of free disk space on your hard drive. Beyond that, there's not much the Genius Bar could do to help.
And when you reboot, if you don't hold down the shift key, you won't be in safe boot mode.