Be sure to ask the supplier of the files. Here's why. To combat piracy some have taken to seeding corrupt and poisoned files. If someone sends you a file that does not work, deal directly with the source.
I use Vuse to download classical music. Much of it comes down in FLAC files which I convert to MP3. Lately, I've been encountering some files which I cannot access to convert or to play. When I right click on the effected files I get a completely different popup than with "good" files, among other things I can't see "Properties" and I can't rename the file.
I have a Compac PC with XP Home, I use Winamp as my media player and convert files from FLAC to MP3 with XRECODE. ITunes won't read them either.