From your post, I assume that you are trying to install Mountain Lion.
What version of OS X are you currently running on your MacBook Pro?
If it is Lion, then simply reboot your computer, and press COMMAND-R when booting. This will take it into the recovery mode. Once there, click on Disk Utility, and perform a "Repair DIsk" on your hard drive. This will identofy and attempt to correct any problems on your hard disk.
If they cannot be reparied it is possible that your Macbook Pro might need a new hard drive.
If you are running Snow Leopard, you can do the same thing by booting from the installation DVD.
The first thing I would try is running Disk Utility (in the Utility Folder which is in the Applications Folder).
Click the "First Aid" tab on top, try verifying the disk and repairing permissions.