I've been able to connect my phone in explorer view to my computer hundreds of times before. Now it suddenly started having this issue. I've tried toggling the USB connection methods (ask on connect, usb mass storage) as well as USB debugging on and off. It pops up with the folder with a few items like the samsung driver file - I've tried installing this and it doesn't seem to make a difference. When I open device manager, I see "SAMSUNG UMS USB Device" with a down black arrow (see screen shot) next to it. I right click to enable and it connects for a split second and shows the folder I want before automatically disabling the USB Device again. Any ideas?