How do I fix my macbook the start up screen with the apple wont stop loading

When you say "load up screen", I assume you mean the Apple boot screen (it has the apple on a gray background).

You might try resetting the PRAM on the macbook.
You can do this by pressing and holding the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

So, turn the macbook completely off. Turn it on and immediately press and hold the Command-Option-P-R keys until the computer reboots and chimes. Once it chimes, release the keys. Your system should boot normally.

You have a bad driver. Reinstall your screen driver or clear your P ram by holding the letters P and R and the control button when you boot your laptop. Hold them until it chimes and reboots.

I would suspect a hard drive or system failure. Try stating up from your system installation disk and running Disk Utilities on your hard drive.

Check for a failing hard drive
Trying booting from the Mac OS X install disc. insert the Mac OS X install disc. press the start button, while holding down the "C" key on the keyboard
Once you are running from the disc. go to Disk Utilities select the hard drive click the "repair permissions" button at the bottom.
If you get any red errors listed or it doesn't seem to finish repairing the permissions you have a failing hard drive and it will need to be replaced.

Download the mac version of opera browser and see if that fixes the problem.
If it does, then simply use that or re-download safari from Apple's site.

insert your Mac OS dvd .. and hold down the c key as you restart. it should launch on the dvd's system and allow you to boot. in the menu select Disk Utility and run the program and see if it can restore your hard drive...

It may need to remount the drive...

Let me know if that helps...

Start the computer and hold down the "C" key when you hear the start up chime. Keep holding down the key until the computer boots into the OS installer. You are going to have to reinstall the OS. Just follow the instructions from there.

When the installation stops, try to press the Escape button to see where it gets stocked. You might have to do a fsck -p command to fix your hard drive.

http://www.retrodata.co.uk/notice_apple_seagate_drives.php