Missing iTunes Tracks. PLS PLS HELP!!!

Hi

After Moving my itunes libary from and external hard drive to the C:// on my windows pc I now have many missing tracks.

The missing tracks are mostly random tracks missing from albums where most of the other tracks from the albums are playable and located in the right locations.

Itunes has tried to find the missing tracks but has failed on several occasions.

I was hoping that itunes 11 would resolve this however not only has it not resolved my issue it no longer asks to locate the other missing tracks once I point it in the location of missing track. (I think I would rather sell every Apple device I own than locate 3000 missing songs individually.)

The frustrating part is that the missing tracks all seem to start with:

file://localhost/C:/Users/Holly/Music/iTunes/Music/Various/BBC Radio 1's Live Lounge Vol.5 CD1/08 08 Pixie Lott - When Love Takes O.mp3

C:\Users\Holly\Music\iTunes\Music\Various\BBC Radio 1's Live Lounge Vol.5 CD1\07 07 The Saturdays - Ego.mp3

So the problem is that itunes has put file://localhost/ infront of all the missing tracks and dont what to do about it.

I know I can copy everything back over and start again but I am also concerned over loosing all the artwork that I've spent hours sorting out.

Please can someone help???

Best wishes