Error 7 (Windows error 126) avFoundationcf.dll not found.

Taken at face value, you're having trouble with an Apple Application Support program file there. (Apple Application Support is where single copies of program files used by multiple different Apple programs are kept.)

Let's try something relatively simple first. Restart the PC. Now head into your Uninstall a program control panel, select "Apple Application Support" and then click "Repair".

If no joy after that, try the more rigorous uninstall/reinstall procedure from the following post:

Re: I recently updated to vista service pack 2 and I updated to itunes 10.2.1 and ever since I did that my itunes won't open any more. Itunes starts but before anything loads a window pops up

Update .netframework to latest version (see apple support)

then

Follow the instructions on this link, basically un-install everything, remove programs that says they are made by apple inc. (using add remove program)

http://www.reimageplus.com/fix-windows-127-error/ (Many thanks to reimageplus.com)

You will also need to check and verify that the following folders have been removed:

• C:\Program Files\Bonjour
• C:\Program Files\Common Files\Apple
• C:\Program Files\iTunes
• C:\Program Files\iPod
• C:\Program Files\QuickTime
• C:\Windows\System32\QuickTime
• C:\Windows\System32\QuickTimeVR

dont forget to remove icloud also

you dont need to delete your itune music library though

If any of these folders still exist, delete them along with their contents. (if you cant delete them, right click and go to properties and then security and change the control of the fold to you)

do this for files under program files and program file (x86) on your computer

once you have deleted everything, restart your computer. Then I repaired my registry using a registry repair program.

Important:- instead of installing itunes I installed quick time, which installs apple application support (this is the corrupt file which is causing all the issues)

i then installed itunes and it all worked fine,

should take no longer than half hour to fix 🙂

hope this helps

Thank you very much FlinneyBee,

My itunes stopped working. Clicking itunes icon the message error 7 windows 5 was displayed. I had tried everything without success. Following your suggestions i solved the problem with itunes. I did exactly what you said: its is necessary to remove all apple programs and reinstall then just after QuickTime installation. I also turned norton antivirus off.