10.5 is garbage on Windows 7 64. I imported almost 600GB (backed-up of course), of music and it started its endless "determining gapless playback" nonsense. Just a continues loop when I moved my mouse. Anyway, I uninstalled 10.5 and it somehow deleted everything up to my "Compilations" folder. Thank God I always backup my music. Frankly, I cannot recall the last time (version) that iTunes ever ran well on Windows. The really early versions ran well but today, iTunes is a bloated and poorly designed application. Actually, it is less of a music management tools as it is more of a marketing/advertising tool for Apple.