I use a IDE hard drive inside a removable caddy, when the HDD is not inside the internal caddy this error occurs; once it's connected it does not occur, so it's also Windows telling you that it canít detect a previously connected hard drive, in my case it is nothing to worry about.
In my case this happens after an electrical outage. I stopped and restart the computer (Win 2K Professional SP3) and the dynamic disk and its partition were available again.
As per ME236086
, this problem can occur if Windows 2000 was re-installed and during Setup a volume on the dynamic disk was deleted and recreated, or another disk partitioning tool like Fdisk was used to create a new partition.
Seems to occur if a harddisk is faulty or the cable is not correctly plugged in.