when I power it on it comes up with the waiting circle going forever.
That's a sign of simple software problem, although it could be something more if there is other unknown factors but I beleive it's only contained to the boot drive which is replaceable.
What I suggest you do is hold the Shift key down while booting the computer, this is Safe Mode and disables some software from running that may be causing your issues. This will give you the opportunity to backup your users files off the machine.
If this works, then go around and update all your third party software or uninstall the ones you can no longer update (using the developers uninstaller, important!), especially the ones that required your Admin password to install, as it put something into OS X itself and that's likely what's causing your problem.
Run through this list of fixes #8 should cure your problems as it replaces OS X with a new copy leaving accounts and files alone, but you might have other issues also so check all the other fixes.
If it comes to having to replace the drive or starting over
Make backups and bootable clones since your on a older OS X version
Lots of great info I have here
Dear DS Store
Thank you very much for the detail reply, I did not know about the safe mode. I tried holding down the shift key and nothing seemed to happen, I have looked thought the help files, too. Don’t think I will be able to do a DIY job on it this time.
I have arranged a collection of my MacBook by a firm in east London; I will let you know the outcome if so it will help anyone who apple is trying a new MacBook too.
Once Again thank you for your help
i finally got my macbook pro fixed. A Company called pc restore installed a new hard drive with a higher GB. My old was 160gb and they replace it with a 500gb, my macbook is working very well and much faster. so it was the hard drive the faulty. it cost less me less the £190. for new hard drive, data recovery and lion installaion.
The technician very was nice, have a word with them.