Mac OSX 10.5.7 boot problem, BSoD

[Switched]

When I tried to turn on my MBP, it went past the 'bong' sound, apple logo and loading wheel and ended up on a blue screen. A loading wheel comes up once in a while but nothing happens.

Prior to this, the only thing I did was change the permission on my hard drive, by taking away the option for 'Everyone' to be able to access it.

This was NOT after the 10.5 update, I bought my Macbook Pro with the 10.5.7 updated beforehand.
The only programs I installed were Windows Messenger and Mozilla Firefox (both Mac compatible versions). I've searched for help in a number of other forums, but nothing worked so far.
Considering I just got this Mac about a month ago, it's very unexpected.

I've tried resetting the PRAM, but it didn't work.
I've also tried to safe boot, but it didn't work, it just stayed at the apple screen.

I've left my Mac disks in the states, and I don't live there anymore, so they're not an option.

Is there a way to fix this?

Please Help!

[cwanja]

You may want to look into the this question here. That user also changed the permissions and I list how to reset the permissions on his user account from the boot disk. If you have any more questions, feel free to post them inside this or that thread.

[Switched]

Thanks for your time, but I managed to fix it using another website.

I had to use terminal and insert a number of codes.

Once again, thanks for answering.

[Signguy]

Switched. I am having the same problem, what was the website you used to get to the codes??

Thanks