Initial startup with question marked folder with a disk already inside

What disk, inside where? What specific model do yo have? What is the hardware configuration.

A flashing question mark appears when you start your Mac

Did it finally start after awhile?

If yes, need to reeducate the system which disk to boot from. Go to System Preferences / Startup Disk, click on the picture of your startup volume and quit. Next time around it will know where to go.

If no, then your startup volume is toast and the bootloader can't start from it. Hold down Command-R before the startup chime to boot in Recovery Mode, then use Disk Utility to do a Repair Disk and Repair Disk Permissions on your Macintosh HD volume. Repeat if Repair errors appear. Hopefully that will cure the problem. Holler if it didn't.

Five ways to eject a stuck CD or DVD from the optical drive

Ejecting the stuck disc can usually be done in one of the following ways:

1. Restart the computer and after the chime press and hold down the left mouse button until the disc ejects.

2. Press the Eject button on your keyboard.

3. Click on the Eject button in the menubar.

4. Press COMMAND-E.

5. If none of the above work try this: Open the Terminal application in your Utilities folder. At the prompt enter or paste the following:

/usr/bin/drutil eject

If this fails then try this:

Boot the computer into Single-user Mode. At the prompt enter the same command as used above. To restart the computer enter "reboot" at the prompt without quotes.

Reinstalling Lion/Mountain Lion Without Erasing the Drive

Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.

When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.

Reinstall Lion/Mountain Lion: Select Reinstall Lion/Mountain Lion and click on the Continue button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

See earlier post on reinstalling Lion.

It wants the network security password.

Are you on wireless or wired? Use the password appropriate to whichever you use.

You don't have FileVault enabled, do you?