I have a question about iTunes on my PC

I just updated iTunes from 10.5 to 10.6. As the auto update wasent working I uninstalled 10.5, then downloaded and installed 10.6 on my windows PC. Before I did all of this I copied my 'Music' folder from within the iTunes Media Folder (in My Music) to my external hard drive. However, I forgot to copy the iTunes Library files. So now, when I copy the Music folder into my new iTunes Media folder it doesnt show up at all in iTunes (my library stays empty, even though its where it should be!).

Furthermore, If I add the music (via file > add folder to library) it puts the songs in and makes the music folder, but in my library 25% of the songs show up with missing artist and album names - some show up as unknown. This is weird as I made the backup yesterday and everything was all organised PERFECTLY in 10.5

Any ideas as to how I can get my music back in library with proper titles etc?

i did back it all up in iTunes Match but not keen on re-downloading at the moment due to the large file size. If all else fails, then I will have to restore from match.

Cheers everyone!

Jamie