2.4mb is left in backup ,first u dont have to use ur internal HDD as to expand ur memory , always mount a usb as media/usb then u can use it to expand ur flash so dont use ur internal hdd for flash expander , also that was a choice & the other alternative choice is pluginskin mover which is also use media/usb to move ur plugins , dont use the both as no point of doing this coz either options u have to expand ur flash & select one of them , i suggest u start with pluginskin mover if u need a light space to be left in ur flash , but if u r going to need more spaces so go for flash expander