Rekordbox music collection lost/cannot be found

Hello,

I'm not sure if if this is the right topic, but thanks for taking the time to read my question...

Since 3 days ago rekordbox can't find any track from my complete music collection...I can see the tracks in rekordbox but when i want to load it in the deck it says: "Loading-error, file could not be found.

I dont know what happend, but all my music is still on my external HDD.

I suspect that windows changed the letter of the disk when i had it unplugged in plugged it back in, but i'm not sure because i cannot open the location of the "missing" tracks to see on wich letter it was before...

Does anyone what i can do to make sure that rekordbox will not have to analyse my whole collection again??

Please help!! 

Thanks in regards,

Sander.