Are you sure you have selected the drive with you SD cad in the right menu (Drop down menu) ?

So.
Insert the SD card in to a card reader (USB deliverd with the tool, or build into your PC)
Note the drive letter Windows has assigned to the drive.
Open update sofware
Wait 2 seconds
Select the drive letter with you SD from the drop down menue at the right side of the window
Wait up to 10 seconds to allow the update software to scan the drive, connect to autel and read the available updates.
Now you should see the updates available for installation, or the messages that there are no updates.

All updates for cars require that you have a "Active Software Period" for your device.