Desktop will not load, stuck on blue screen -- please help!

Question

As I can see, many other Mac users have encountered the same problem that I now have: the dreaded ‘blue screen of death’. About a week ago, any internet browser that I tried to open (Safari, Firefox) would freeze after loading its home page, and tell me that the application was not responding. After force quitting and restarting each program a couple of times, with no positive response, I decided to restart my computer to see if that would do the trick. Upon booting up, it then started the same sequence that it is still doing now: first a grey screen will briefly show, then a white screen with the apple logo and a turning dial beneath it, followed by a blue screen which will show a window that says “Starting Mac OS X” with a progress bar beneath it, which will fill to various points (sometimes only 1/8 of the way, while other times it fills completely), but it always leads me to the same screen – solid blue with a black arrow that will occasionally be replaced with a turning dial, only to go back to the arrow again. I am using a PowerBook G4 with the Tiger version of OS X. No applications were running whenever I first decided to restart my computer, and to my knowledge, all software and security patches were up to date and fully installed.
I’ve researched and tried every possible option that I’ve come across, listed below with the results they yielded (if any):
 Holding the Command/Option/P/R keys upon startup (screen stays blank, and the computer continues to ‘chime’ until I release the keys. I have allowed it to chime a couple of times before I stop holding the keys, but it always leads me back to the same blue screen)
 Holding the Shift key upon startup (leads me to a screen that has an icon of my hard drive and two arrows. Clicking the left arrow does nothing, the hard drive icon does not respond to being clicked, and the right arrow starts the loading process which again ends with the blue screen)
 With the first OS X Installation disc that came with my computer inserted into the disc drive, holding the C key (nothing happens; sequence as normal)
 With the first OS X Installation disc that came with my computer inserted into the disc drive, holding the Option key (same results as holding shift key with no disc)
 With the first OS X Installation disc that came with my computer inserted into the disc drive, holding Option/Command/Shift/Delete (a grey screen appears with the icon of a folder, a question mark briefly flashes before being replaced by the two-toned blue face Mac logo. After continuing to hold the keys with this folder and face on the screen, I get no response, so release the keys and the computer continues to enter the white screen-blue screen sequence)
 Holding the Command/Option/O/F keys upon startup (a white screen appears, and following advice I have seen on other forums a type ‘reset-nvram’, then return, then ‘reset-all’, then return. The computer reboots and the sequence continues as usual. I have also tried holding the Command/Option/P/R to reset the PRAM immediately after leaving the white Open Firmware screen, allow the chime to sound a couple of times as before, but still I get no results)
 While on the blue screen, pressing the Command/Shift/Q keys (alas, I am the only user on the computer, so I cannot try to remedy my problem by signing into another account. From the screen the appears, I can either shut down, restart, or put my computer to sleep, or enter my password which leads me back to the same blue screen again)
I apologize in advance if I’ve included a lot of extraneous information, but I just wanted to cover the options I’ve already explored so as not to waste your time if you had any of these in mind. I’m going to post this on a few different forums just to make sure I have all my bases covered, but anything you have to offer in the way of suggestions would be greatly appreciated. If you could post your advice in layman’s terms that would be even more helpful; I’ll probably need exact, step-by-step instructions if required to start my computer in ‘safe mode’ or anything else an average user would not be familiar with. I know this is a lot to ask, so I thank you in advance for taking the time to read through this and offer any solutions that you may have.

Answer 1

Hi amnicolekidman, and a warm welcome to the forums!
Although you don't specify your Mac, it sounds like you have real HW problems, likely the HD.
Tough without a Tiger Disk, but try fsck...
To use fsck, you must run it from the command line. Unlike using your mouse to open an application to do something, you'll need to type a text command at the prompt (#) to tell fsck what to do. The Terminal application (/Applications/Utilities) and single-user mode are two examples of command-line interfaces in which you can type such commands. To use fsck:
1. Start up your computer in single-user mode to reach the command line. Hold CMD+s keys down at bootup.
Note: If necessary, perform a forced restart as described in the Emergency Troubleshooting Handbook that came with your computer. On desktop computers, you can do this by pressing the reset/interrupt button (if there is one) or holding down the power button for several seconds. On portable computers, simultaneously press the Command-Control-power keys. If your portable computer doesn't restart with this method, you may need to reset the Power Manager.
2. At the command-line prompt, type /sbin/fsck -fy
3. Press Return. fsck will go through five "phases" and then return information about your disk's use and fragmentation. Once it finishes, it'll display this message if no issue is found:
** The volume (nameofvolume) appears to be OK 
If fsck found issues and has altered, repaired, or fixed anything, it will display this message:
*** FILE SYSTEM WAS MODIFIED *** 

Important: If this message appears, repeat the fsck command you typed in step 2 until fsck tells you that your volume appears to be OK (first-pass repairs may uncover additional issues, so this is a normal thing to do).
4. When fsck reports that your volume is OK, type reboot at the prompt and then press Return.
http://docs.info.apple.com/article.html?artnum=106214
Then Safe Boot , (holding Shift key down at bootup), off the HD & use Disk Utility from there to Repair Permissions, reboot once more.