AppleWin registers the following file types as "Disk Images": *.do, *.dsk, *.nib, and *.po. Double-clicking a disk image in the Windows Explorer will automatically load and boot the disk. While older versions of AppleWin started a new instance of the emulator for every disk started in this manner, current versions of the emulator will simply replace the current disk if there is an instance of the emulator already running.
You may also drag and drop a disk image from an Explorer window to the AppleWin emulator window to load and boot the disk. Dropping the image exactly on one of the drive buttons will insert it only into this drive without booting. For example: drop "Pascal1.dsk" to drive 1 and "Pascal2.dsk" to drive 2, then click the the Run button to bring up UCSD Pascal.
AppleWin now allows you to open a disk as read-only. To do this, click the checkbox for "Open as Read Only" in the Select Disk Image dialog. This works like the physical write-protection mechanism on a real Apple //e floppy disk.
If a Disk Image name is to long to read in the Toolbar, simply pause the mouse cursor over a drive button to get a tool-tip with the full name.