Question about Stratix IV act like disk drive?

I have project that build hardware system on FPGA, it contains module SGDMA, PCIe Avalon MM, DDR3 Controller and HDMI Controller.

PC communicate with FPGA through PCIe Link.

I used windriver generate .INF (mass storage) and install this driver into PC. It shows up new "Storage Volume" in Device Manager but I expect It show up something like drive C: D: E: in File Explorer.

Please give me information about this issue? How to get it as a hard drive and display it in file explorer?

I am very grateful for your help!

Thanks and regards!