Sorry, I messed up and did not clarify, That is the OSX CD I was talking about in the first post.
So can you put your Mac CD in your machine then shut it down.
Once it is off can you then power it back up and then press and hold down the C key on your keyboard till you see the apple load wheel under the apple icon and then let go.
Your Mac should open to the installer menu and when it does can you then choose English from the menu and click the right arrow.
Next can you click the Utilities menu on the top toolbar and choose Disk Utility to open it
When it opens can you then choose the First Aid tab and select your OSX disk on the left
You should then have the option to verify disk and repair disk, If you could run a verify permissions first then run a verify disk then run a permission repair and a disk repair, If the disk repair gives you an error can you run it a second time.
Once that is done can you then restart your Mac and let me know if it will now boot cleanly and run correctly.
If not can you then boot from the Mac CD one more time by holding the C key down as you power up and then can you try to perform an Archive and install if you wish to keep your files or if you can afford to loose it all can you perform an Erase and install and just follow the prompts then let me know if you have any issues.