If you're using software RAID 5, you have three or more dynamic disks should be configured. If you lose a single disk from the set, no data is lost. Because of data and parity information stored on the remaining disks. If you need to replace the disk follow the procedure below.
Step 1. Replace the dead disk with a new on in the server.
Step 2. Access the Disk Management node of Server Manager.
Step 3. Your replacement disk will be found and you'll be prompted to initialize the disk.
Step 4. Once it's initialized, right-click the disk and select convert to Dynamic Disk…
Step 5. Ensure that only your new disk is selected to convert and click OK.
Step 6. Scroll down to the disk that's missing for your RAID 5 set, right-clicks it, and select Repair Volume…
Step 7. Your new disk will be listed to be used as the replacement. Make sure it's selected and click OK.
Step 8. Your RAID 5 volume will now go into a Re syncing state, which can take a long time—it has to repopulate the data/parity information on the new disk to make the RAID 5 volume fault tolerant again. Right-click the missing disk, which no longer has any associated volume, and select Remove Disk.
Try and minimize the workload on the RAID 5 while it's re syncing because a heavy load will slow down the rebuild.