I came a problem with my Machine Hanging, not booting correctly, restarting etc.... it drove me nuts. It took me days and days to trouble shoot everything.
Maybe this problem you're having might be the same thing I went through.
I finally figured out my problem and it came down to the setting in bios about USB 3.0 XHCI/EHCI settings ( I had a USB Wireless Mouse plug in this port)
After days or changing RAM, reformatting HD, replacing HD, Cleaning FANS.... I mean the whole works....Then for some reason I unplug the USB wireless mouse and the damm thing worked (That light the bulb on top of my head). So I plug it in again and it acted weird again. So I thought the MOUSE is shot. Changed it to a WIRED mouse in the same USB 3 port and..... same problem.
Then I said the port is bad, don't use it...... I went back to BIOS and saw this USB 3 setting. It say, "If your having problem with XHCI mode, change it to EHCI mode.
After I changed it, put back my Wierless USB mouse in the port and..... PROBLEM IS GONE FOR GOOD.
My PC defaulted to XHCI setting.
Look in the BIOS setting for USB 3.0 setting and set it EHCI.