There appears to be some sort of issue with the file system on Disk 1 since it's not showing as either NTFS or FAT32.
You might see if you may be able to use the free Partition Wizard
to either try and recovery Disk 1 or assign a drive letter to Disk 1.
If that fails, then you could use the link below to create a live Ubuntu disc to try and recover any files you wanted from Disk 1. Use Ubuntu Live CD to Backup Files from Your Dead Windows Computer - How-To Geek
Afterwards, and there's nothing else you want on the drive, it looks like you may need to run the clean
command on Disk 1 to completely wipe it clean, then format it give it a drive letter.