Select user offers a list of the handheld users to install to. Choose the desired user.
This is a USB-connected device checkbox tells whether or not the device is connected by USB. This is currently only used on Linux, Mac and MSW don't use or need it. On Linux, if this checkbox is selected, then when it is time to send files to the handheld, Plucker Desktop will pause and show a dialog, informing you to press the HotSync button, which will connect your USB to your Linux OS so that files can then be transferred.
By default, the output will install into the handheld's RAM memory. Mac and MSW also allow installing the file directly to a Card on the handheld. Choose either The handheld's RAM memory, The removable SD/MMC card, or The removable MemoryStick as desired.