This is my first computer build, and I am to the point where I have to insert my optical drive into the external 5.25 drive bay. Now, I decided I would just use the drive from my 3 year old Dell. So I mounted the brackets onto the sides of the drive, and now when I go to slide the drive into the drive bay, It won't fit, and judging by how easily it fit into the dell case, I'm confused as to how I am going to get this thing in. Are all drives made the same size, or am I doing something wrong ? Case http://www.amazon.com/Antec-P160W-Anodized-Aluminum-Enclosure/dp/B000BPRGKG