In the file requester, give your new hard drive a name.
Enter 2000 into the new hard disk image file size field, check 'Dynamic HDF' and click on 'Create'. Also, from drop down menu that says “UAE” choose “A600/A1200/A4000” and click “Add hard drive” button. For this I’m using a PC, Adaptec SCSI controller and WinUAE.