1. While not officially supported by Dell, one of my fellow geeks at work has the same model currently running 8.1 for his sons' school work.
2. A black screen does circa indicate hanging when installing 8.1 but could also just be looking for drivers over a slow network or the i3 chip might be trying to unpack something large… how long a hang (5-10 minutes) are we looking at?
3. Is the install coming from a disc or usb?
Incompatible file systems would be my first guess given that windows 7 uses mbr and would have a hidden (locked) recovery drive because it is a laptop whereas 8.1 wants the new efi format and also should be installed on a clean (unallocated space) hdd for best practice… by all means put 7 back on afterwards if you want it to dual boot and obviously you will have backed up the hdd before you formatted it.