I've had a problem with my system that I discovered after I tried to add some songs to my music collection. I keep all my music files in the default Music folder. All of these files come from another system (XP), and are transferred to my W7 PC.
Up until 1 week ago, I transfered my files to the Music folder, and dragged/dropped them to the Media player to instantly add them to the library - and, of course, I could play them independently as mp3 files. Yesterday, I replaced the default WMP with the Zune media player, and installed SP1 for W7 and several important updates (for some reason my system could not perform updates for a long time, so I installed SP1 via CD and then everything went smooth).
After all these, I decided to transfer some more mp3 files from my windows XP to my W7 system using a USB flash drive. However, when I placed them in the Music folder, I could not add them to the Zune music library, and I could not play them independently as mp3 files, getting the message that the type file was not valid. The strange thing was, when I copied the files to Desktop instead of the Music folder, i could play them and handle them normally. I could not perform any action on the just transferred files, when I placed them in the Music folder, like copy or move, only undo the paste, not even with admin privileges.
After much searching, I saw that the problem was in the access and owner permissions and went on to change the owner settings of the new files and added the SYSTEM and Administrator users as users with the appropriate rights on the files, and everything was fixed. However, I will be transferring hundreds of music files in the future, so changing each and every file's properties by hand is not very efficient.
So my main question is, why did this automatic change in the permissions happen, and how can I avoid it? Does it may have something to do with the updates I installed, or that the files came from another PC? All the previous files I had transferred some time ago had no problem. The new files, as I noticed, had an owner which was a user who doesn't exist on my system, and did not have the system and administrator as an owner like all the other music files did. I did not check the owner state of the files when I placed them in another place from the start. Thank you in advance.