Hi there,
Is this secondary or OS drive? Is this a new drive or you have some data on it? It would be helpful if you provide a screenshot of Disk Management.
In case it is a new drive, you will need to go to Disk Management -> Initialize -> Partition & Format.
In case it is not a new drive and appears in Disk Management just fine(healthy partitions, file system), you need to see if it has letter assigned. In case it doesn't have one, you can assign one.
Let us know how this goes,
D_Know_Wd