Q : Since my HDD possibly might give out soon and I don’t want to have to go through the process of setting everything up again, I was thinking of getting a secondary HDD to mirror my data onto with a RAID 1 configuration. My question though, is if I can set this up without losing my data already on my original HDD. Thanks in advance for the help!

A : It depends on your RAID solution. Many RAID solutions format a disk when constructing a RAID or adding a new disk. Desktop versions of Windows Windows have a built-in software RAID capability which will attempt to preserve your data during conversion. However, you should still back up your data in case something goes wrong.

  1. Start Disk Management. Press Win+r, then type diskmgmt.msc and press Enter
  2. Right-click on your data disk, click Convert to Dynamic Disk, and go through the wizard.
  3. Right-click on your data disk, click New Mirrored Volume, and go through the wizard.
  4. Right-click on your new disk, click Add Mirror, and go through the wizard. (Note: the “new” disk must be a dynamic disk and must be unallocated. If it already has partitions, you must delete them first.)

See HowToGeek for more detailed instructions and screenshots (but ignore the article’s title–RAID1/mirroring is NOT a backup!).

Source : https://superuser.com/questions/677564/can-a-raid-1-be-created-without-losing-data