Asus Pedestal/5U Rackmount Server TS500-E4 Server - Manual (Page 184)

7-8 Chapter 7: Driver installation
4. Select fd0 using the <Tab> key when asked to select the driver disk
source. Press <Tab> to move the cursor to OK, then press <Enter>.
3. Select Yes using the <Tab> key when asked if you have the driver disk.
Press <Enter>