MP3's play fine on all my windows7 computers and thus WMP12.
XP or Vista with WMP11 Don't play mp4's, So I'm going to take
the time to see that microsoft page you are referencing.
(mp4 isn't listed by microsoft, but it doesn't specifically
exclude it either) But I've been playing mp4's for years.
MKV and FLV do not play in WMP which is why I convert MKV
and FLV to mp4 as standard practice.
Ultimate Tag Scanner is also free.
as for "large number of files" I've currently got just over 36,000 Audio files, 373 Full Length Concerts & 400-ish feature films and another
3500 "short" (<10min) Videos.
Simply being unable to play FLV files is not the entire issue with FLV's
Windows7 won't even show thumbnails or do previews of FLV, I don't know about Windows8.
What I prefer for buying new content is to buy a physical CD,
"ripping" it, creating mp3's and tagging it myself.
Working from Vinyl? No.
Since the about 1990 everything is digitally mastered anyway
so any music would need to be converted to analog to put it on vinyl
anyway, then converting it back to digital?
People complain about "lossy" mp3 but reality is that analog vinyl
probably loses more signal being reduced from the digital master
than that which is stripped away creating mp3 from CDDA.
And that's presuming broadcast quality turntable and recording from a "Virgin" vinyl disc. Vinyl suffers a loss of quality every time it's played.
If I could buy new audio content as FLAC or WAV I could
live without a a physical disc.