Can`t write tags

Im using Win7 64 bit and Im administrator in this PC
In my last PC MP3Tag worked perfectly (XP)
Now, every time that i try to tag a file gives me this error: "File:C\Music\XXXX cannot be opened for writing.
The files aren`t "read only" and I cannot see the reason of the error.
Can you help me please?

It is not enough to be administrator on a pc - that was the way with XP.
You have to be the owner or grant permissions to "everyone" to access the files for modification.

See e.g.
as a Microsoft help page.

Thanks but it`s not enough, I did as the article says and still get the message, any other help, please?

You can see the owner in the Windows Explorer if you add a column for "owner".
If that columns shows only letter&number-combinations, you should change that to the current user.

Yes I did see those number and changue as the article suggest But nothjing happens.
In XP if you press richt click>Properties>Details was possible add artist or albums names now in 7 I cannot do that, maybe its a windows problem? So far Im searching for an answer (the story of my life).
Thanks for your help

So, there we are: you are not the owner.

To change the owner:
Select the top folder.
Right-click on the folder and select "Properties"
Go to tab-folder "Security".
Click on the lower "enhanced" button.
Click on the tab folder "owner"
Tick "Apply to all subordinate objects" (my translation - it's the only check box in that dialogue)
Click on "Add"
In the Input box enther most of your current user-id and click on "Check name".
Click on OK until most dialogues are closed again.
Depending on the number of files, it may take a little time until all files have become a new owner.

Probably, once you got the owner right, you will be able to edit the tags in Windows explorer again, yet I would not advise it as WE removes any user-defined fields from files.