The suspect in your case might be the hard drive.
I recommend you to run the HDD manufacturer utility and low level format it.
Had similar reinstalling issues with W7 on a "strange" refurbished Seagate HDD on my 970-UD3 ,after testing the useless W8
Same thing was happening ,the install would hang at some point.
After formating it several times at low level and after it forgot it had 640 Gb (it kept showing 32 Gigs for some time
) , it recovered and finally allowed me to install W7.
Try AHCI with ESP on or off and the plain simple IDE Mode.
Try with some other HDD as well.
Keep in mind that low level format will destroy all data and/or deleting track 0 will destroy all partitions on the HDD.