iTunes cannot add to library (Solved)

Ran into this problem today on my Win 7 Professional machine.

Have some MP4 movies which I generated from recorded programs.

Have movies on the local hard disk, as well as on an external disk.

When I added the local folder to the library, the movies were added.

When I tried adding from the external disk, some movies, but not all were added.

I have created all the MPEG 4 movies the same way using Aunsoft BluRay Video

Converter Ultimate, so the format of the video for working and non working are OK.

Note that this solution is translated from a non-English Windows 7 machine.

I tried copying a file from the external hard disk to the local hard disk, and then

iTunes could add the file to the library.

Since some files ARE detected on the external hard disk, just moving it

to the local disk, is not the real solution.

Checked the properties of a non-working file and a working file.

Apparently the non-working file has a "owner" looking like

"S-1-5-21-0123456789-012345678..." while working files

has the owner "<machine>/<user>".

I then duplicated a non-working MPEG-4 file on the external hard disk,

and then the copy could be detected, but not the original.

The original still had the owner "S-1-5-21..."

I tried changing owner of a complete directory and all underlying files.

I could see that the owner was changed on a file, but that still did not help.

I the tried to edit the properties of a single MP4 file.

Open the properties, and select the "security" tab.

On non working files, i had "Group or User name:"

SYSTEM

Unknown account ...

Administrators (<machine>\Administrators)

User (<machine>\Users)

but my own user identity was not there.

<machine>\<user>

Clicked the "edit" button, which opens a new popup window.

Click on "Add", and yet another popup opens

Click on "Advanced" and the "Choose User or Group" popup opens.

Click on search, and you will get a list of identities.

Choose the identity "<your-user-name> <MACHINE>" and press OK.

Time to exit all popups by pressing OK.

In one of the popups you can define the access rights for the user.

Make sure that you have full rights, and then continue to exit

the popups.

Now (if this was your problem) you should be able to add the file.