Which Disk Is \Device\HardDisk1\Dr1?

To find out which hard disk is \Device\HardDisk1\Dr1, run this PowerShell cmdlet:

Get-PhysicalDisk | Select -Prop DeviceId,FriendlyName,SerialNumber

This will show a list of disks, and the DeviceID number relates to the HardDisk number! You should be able to work out which physical disk this is from the name, or alternatively, you can find out which disk is \Device\HardDisk1\Dr1 from the serial number, which will be printed on the disk.