Q: iTunes Error 7 (Windows error 127) after installing iTunes 64-bit for Windows

Taken at face value, you're having trouble with an Apple Application Support program file. (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. Then head into your Uninstall a Program control panel, select "Apple Application Support" and click "Repair".

Does iTunes launch properly now?

ive done all this too

Steps

1. Remove iTunes and related components from the Control Panel

Use the Control Panel to uninstall iTunes and related software components in the following order and then restart your computer:

1. iTunes
2. QuickTime
3. Apple Software Update
4. Apple Mobile Device Support
5. Bonjour
6. Apple Application Support (iTunes 9 or later)

Important: Uninstalling these components in a different order, or only uninstalling some of these components may have unintended affects.

still not working

well i tried it once, it didnt work for me but idk if it would work for you... i found it here http://support.apple.com/kb/ht1923

its up to you if you wanna do it. im doing it again right now and im hoping for different results. ill reply what happened after im done

GREAT NEWS it worked this time

ok the link i posted earlier follow all those instructions in step 1 VERY carefully

then do step 2 and make sure all those files are gone

restart your computer and go to itunes and install it =D

Thanks Sabrina,

After a failed update of iTunes (caused by a power outage), I received the following error trying to launch iTunes:

"iTunes was not installed properly. Please re-install iTunes. (Error 7)."

I followed the instructions on http://support.apple.com/kb/TS3074 but it didn't work. Clearly the .Net 4 Framework had nothing to do with the problem.

I had also tried uninstalling and reinstalling iTunes, but this also didn't help.

I followed your adviceand uninstalled all Apple / iTunes related products as listed in http://support.apple.com/kb/ht1923 and this worked.

Problem solved!

Thanks.

Will my synced songs in my ipod be lost if I remove itunes and its components?

You can email this person for help

<Email Edited By Host>

I followed all of the procedures including uninstallation procedure, verify uninstallation procedure and reinstallation procedure.  That did not work for me. 

Next, I then tried uninstallation procedure, verify uninstallation procedure and reboot.  I then ran the Repair option for .NET and rebooted.  I finished that off with a reinstallation procedure.  That did not work for me.

At this point, I realized that some registry error must still be present that I am simply not seeing that it causing the failures. 

Here is what I did.. I installed ccleaner utility so that I could check for registry errors after uninstallation.

Step 1 - Uninstall iTunes using designated procedure for Apple - In the exact order that Apple specifies

Step 2 - Verify uninstallation of iTunes using designed procedure for Apple - deleting all folders.  I found no folders so I just rebooted at this point.

Step 3 - I again, repaired .NET with reboot. 

Step 4 - Open ccleaner and look for any Itunes related Registry Errors. 

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SharedDlls]

"C:\\Program Files\\iPod\\bin\\iPodService.exe"=dword:80000000

AHA! This entry for iPodService.exe still exhisted.  So I had no folders on the PC, no installs on the PC and no services running.... BUT this was still in the Registry. 

Step 5 - Delete only the Registry entry above.  NO REBOOT

Step 6 - Reinstall iTunes64.exe

That worked.  After I removed that persistent registry key the installation was successful and iTunes is now running on my PC successfully.  Glad I found these forums and I was not the only one having this problem.

Good Luck!

This is what fixed my problem.

Brilliant. Thanks a lot. I've wasted a couple of hours on this nasty bug, & trying all the other suggestions across various threads again and again.

I now find I had the same registry entry hanging on, despite uninstalling & wiping everything again and again. Having now deleted this key, (I don't even have an iPod), & iTunes 11.1.14 now opens at long last.

But WHY is this bug not fixed? Enough people are suffering with this across the forum. WHERE is Apple support on this?

It should have been added to their page at 

http://support.apple.com/kb/HT1923

by now, why hasn't it???

It's not good enough!

Re:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SharedDlls]

"C:\\Program Files\\iPod\\bin\\iPodService.exe"=dword:80000000

AHA! This entry for iPodService.exe still exhisted.  So I had no folders on the PC, no installs on the PC and no services running.... BUT this was still in the Registry.

Step 5 - Delete only the Registry entry above.  NO REBOOT

Step 6 - Reinstall iTunes64.exe

I just went into Control Panel - then System and Security - then Review your computers status - then Recovery. Go to the restore point prior to trying to do the update.   This does not delete any files(movies, music etc).  Worked fine for me

I have had this problem also.

It started when I was asked to update iTunes.

The version before last I also had a problem where iTunes would open but then crash. I looked up the internet and found this fix which worked brilliantly: copy/past of QTMovieWin.dll.

Clearly what has happened is that Apple fixed this problem in the latest release but what I found was the the fix for the time before causes  the Windows error 127 problem.

If you did this before simply go to C:\Programme Files (x86)\iTunes and delete QTMovieWin.dll and iTunes will open without trouble

I was traveling to Mexico and I went to open I-Tunes on the plane and that error message came up.  After reading many posts, I thought I was going to have to spend hours trying to fix this problem while on vacation.  I am so happy I kept on reading and found richardsealy's post!!

I just tried the fix from richardsealy said to do on January 29th, 2014 and it FIXED it.  I did not have to do any of the uninstalling and reinstalling of I-Tunes!!   THANK YOU SO MUCH!!