Unable to start QuickTime 7 in Macbook Pro

[Jahi]

I am using Macbook Pro which is running the Mac OS X (10.6.7) in it. Until yesterday my Macbook Pro was working smoothly without much issue but today morning it has started showing me few problems. Suddenly the QuickTime 7 software is not starting. When I try to open it, the screen flashes for a second and closes back again. I am unable to play any media file and am finding it difficult to solve the problem. Does anyone know what must have caused this? Please help me.

[!const]

As you said that the problem was not there until yesterday, you should perform System Restore with the help of the System Restore CD that is provided when you purchase your Mac. Remember to take Backup of all the important data onto an external drive or any other storage device. Perform the following steps:

• Insert the Restore System CD in the CD/DVD drive. Restart your system and boot up the Restore system disk.
• Search for the system folder and disable it. Locate the folder and open it. Find the system icon; the one having suitcase image, and drag it into the preference folder. Now rename the folder as “disabled system folder”
• Start the Apple Software Restore application and select OK. Choose the target where you wish to install the fresh system folder. Follow the on-screen instructions and press the restore button.
• Once you are done with the system restore process click “Quit” option.
• Select your hard disk as the startup source when “Startup Disk Control Panel” appears.
• If Startup Disk control panel appears, reselect the hard disk as the startup source.
• Complete the restoration steps by Restarting your system.

[sergioKomic]

You should probably uninstall/remove the installed QuickTime Player 7 as it must have got corrupted, that is why they are not able to play any file. You can remove it from your system by just dragging the QuickTime Player 7 icon into the TRASH. If you have installed the application inside a folder then you can even drag and dump the entire folder. Also try to search related files of QuickTime 7 in Library folders and its subfolders. Discard them if you wish to but remember that this kind of removal can disable your system if you remove anything wrong. Once you done removing the QuickTime application and related files and folders, search for the latest version of QuickTime 7 on internet and download it from the official website of Apple. Once you done with all these steps install the new QuickTime 7 and check if that works well or not.

[CodGuru]

Once you done removing or uninstalling the QuickTime Player from your system, you can re-install it by this using the Mac OS X install DVD. If you have got the DVD then follow these steps:

• Put in your Mac OS X Install DVD inside the DVD drive.
• Click on the “Optional Installs” folder and double-click on "Optional Installs.mpkg".
• Search for the QuickTime 7 option, select it and click Continue.
• Wait for your system to install QuickTime Player 7 in your system (to be specific then it is installed in your Utilities folder.)

[GeforceUser]

You should search for /Library/QuickTime and ~/Library/QuickTime and throw them into the trash. Search for .plist files with quicktime in their names and dump them into trash. Or you can also use these few applications to completely remove all the related files to QuickTime or any other files.
Amnesia, AppCleaner, AppDelete, AppTrap, AppZapper, CleanApp, CleanMyMac.
Once you are done removing/uninstalling the earlier files of Quick Time, Reinstall the new setup of QuickTime 7.0 in your system.

[Blazej]

I would suggest you to create a new user account in your system and then check whether your files are running properly under that account. If you are able to play them on the newly created account then the problem is in your current user account. And if the problem exists in the new account also then you should create a pristine Snow Leopard external start-up drive. Once you are done making the external drive, check if everything works fine when you boot the external drive. If everything is working perfectly then probably you are having infection in your main system/configuration files.