Computer Crash ER: incorrect paramater/can't access drive

I'm running windows XP home on a custom made professional music computer.  I have a 80 GB l c: drive as well as a two 120 GB  Maxtor SATA 8mb Raid Configured 0. Last night I added a sample player piece of software that has been tested with my Cubase SX3 sequencer and verified to work.  To make a long story short....my computer crashed and started to run very very very slowly.  

I  restored to previous date but it sttill ran very slow.  I used Registry Mechanic and it took about three hours to go through its paces.  It normally takes about 5 minutes.  It found over 100 registry errors and now things appeared to run normally.  HOWEVER when I went to check on my music files on the D: drive (raid )) I got an error message saying  the drive can't be accessed  D: incorrect parameter.  I checked in the control panel/system and after a long wait I was able to access the device manager.  It saw the D: drive and there were no error messages.  

What can be done quickly about this as I'm in the middle of a PBS special film project that I'm composing music to.

Thanks,

Steve