Thanks for the reply and apologies for the lack of information -- I will provide more detail.
The motherboard model for my machine is "GA-78LMT-S2 rev 1201", the specs for which can be found exactly here: http://www.gigabyte.com/products/product-page.aspx?pid=4643#sp AMD FX(tm)-4300 Quad-Core Processor 8GiB RAM Radeon(TM) RX 460 Graphics The machine has one internal hard drive connected to one of the SATA slots, "TOSHIBA DT01ACA100 ATA Device", 931.51 GiB. On it, I have installed Windows 10 64-bit with no problem. I boot Windows, install the latest Cygwin for a "dd" command, plug in my SanDisk 16GiB USB thumbdrive, and run the following commands on a privileged Cygwin bash prompt: $ /sbin/fdisk /dev/sdb (to ensure that /dev/sdb refers to my USB thumbdrive, it does) $ dd if=install60.fs of=/dev/sdb bs=1M $ sync Now, before I proceed let me explain what I see during a normal boot (i.e. when there are no USB's connected at boot). 1) The computer is totally off, the monitor is pitch black. 2) I press the ON button, the fans start spinning, the monitor is still pitch black, the computer is presumably in POST. 3) After a moment, the monitor turns on its backlight, but only displaying black. 4) The monitor "flickers" (backlighted-black to pitch-black, and back) 5) Some text appears on the screen, if I'm not mistaken this is the BIOS doing preliminary hardware recognition (I see text regarding PCI buses and such). 6) Flickers again and now I see Windows logo, etc. If I hold in the DELETE key during bootup, it will display a blue background BIOS menu at exactly STEP 5 in the above list. Now, when I turn the computer off, plug in the USB, and turn it on, the computer will actually seem to "halt" or "freeze" at exactly STEP 3 in the above list. The computer does not respond to anything, being stuck at step 3 with a backlighted black monitor. This also means that I cannot even reach the BIOS menu, because that is at STEP 5! Of course, if I shutdown and unplug the USB, the computer can boot again. Another peculiarity is, if I boot into the BIOS menu with the DELETE key, and THEN plug in my USB thumbdrive, the computer will "freeze" here as well -- the monitor stays constant and keyboard presses are completely ignored. One might think that the BIOS cannot handle USB thumbdrives properly, but if I format FreeBSD 11.0 USB image onto it with the exact same procedure as above, the BIOS has no problem at all booting it (and I've happily used FreeBSD on this machine in the past). This is why I think there is some quality in install60.fs that my BIOS simply chokes on when it tries to recognize it as a device. I honestly do not know what it can be. In addition, I have tried using the "Rufus" Windows utility in place of "dd" to format my USB drive, to no avail. I also tried fiddling around with obvious BIOS options, to no avail. Here is the output of dmesg when I booted from a FreeBSD USB installer image: Thanks in advance for any help. Copyright (c) 1992-2016 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD is a registered trademark of The FreeBSD Foundation. FreeBSD 11.0-RELEASE-p1 #0 r306420: Thu Sep 29 01:43:23 UTC 2016 r...@releng2.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC amd64 FreeBSD clang version 3.8.0 (tags/RELEASE_380/final 262564) (based on LLVM 3.8.0) VT(vga): resolution 640x480 CPU: AMD FX(tm)-4300 Quad-Core Processor (3816.96-MHz K8-class CPU) Origin="AuthenticAMD" Id=0x600f20 Family=0x15 Model=0x2 Stepping=0 Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT> Features2=0x3e98320b<SSE3,PCLMULQDQ,MON,SSSE3,FMA,CX16,SSE4.1,SSE4.2,POPCNT,AESNI,XSAVE,OSXSAVE,AVX,F16C> AMD Features=0x2e500800<SYSCALL,NX,MMX+,FFXSR,Page1GB,RDTSCP,LM> AMD Features2=0x1ebbfff<LAHF,CMP,SVM,ExtAPIC,CR8,ABM,SSE4A,MAS,Prefetch,OSVW,IBS,XOP,SKINIT,WDT,LWP,FMA4,TCE,NodeId,TBM,Topology,PCXC,PNXC> Structured Extended Features=0x8<BMI1> SVM: (disabled in BIOS) NP,NRIP,VClean,AFlush,DAssist,NAsids=65536 TSC: P-state invariant, performance statistics real memory = 8589934592 (8192 MB) avail memory = 8250204160 (7868 MB) Event timer "LAPIC" quality 400 ACPI APIC Table: <GBT GBTUACPI> FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs FreeBSD/SMP: 1 package(s) x 4 core(s) ioapic0: Changing APIC ID to 2 ioapic0 <Version 2.1> irqs 0-23 on motherboard random: entropy device external interface kbd1 at kbdmux0 netmap: loaded module module_register_init: MOD_LOAD (vesa, 0xffffffff8101c950, 0) error 19 vtvga0: <VT VGA driver> on motherboard cryptosoft0: <software crypto> on motherboard acpi0: <GBT GBTUACPI> on motherboard acpi0: Power Button (fixed) cpu0: <ACPI CPU> on acpi0 cpu1: <ACPI CPU> on acpi0 cpu2: <ACPI CPU> on acpi0 cpu3: <ACPI CPU> on acpi0 attimer0: <AT timer> port 0x40-0x43 on acpi0 Timecounter "i8254" frequency 1193182 Hz quality 0 Event timer "i8254" frequency 1193182 Hz quality 100 hpet0: <High Precision Event Timer> iomem 0xfed00000-0xfed003ff irq 0,8 on acpi0 Timecounter "HPET" frequency 14318180 Hz quality 950 atrtc0: <AT realtime clock> port 0x70-0x73 on acpi0 Event timer "RTC" frequency 32768 Hz quality 0 Timecounter "ACPI-fast" frequency 3579545 Hz quality 900 acpi_timer0: <32-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0 acpi_button0: <Power Button> on acpi0 pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0 pci0: <ACPI PCI bus> on pcib0 pcib1: <ACPI PCI-PCI bridge> irq 18 at device 2.0 on pci0 pci1: <ACPI PCI bus> on pcib1 vgapci0: <VGA-compatible display> port 0xee00-0xeeff mem 0xc0000000-0xcfffffff,0xdfe00000-0xdfffffff,0xfdf80000-0xfdfbffff irq 18 at device 0.0 on pci1 vgapci0: Boot video device hdac0: <ATI (0xaae0) HDA Controller> mem 0xfdffc000-0xfdffffff irq 19 at device 0.1 on pci1 pcib2: <ACPI PCI-PCI bridge> irq 18 at device 6.0 on pci0 pci2: <ACPI PCI bus> on pcib2 re0: <RealTek 8168/8111 B/C/CP/D/DP/E/F/G PCIe Gigabit Ethernet> port 0xde00-0xdeff mem 0xfdbff000-0xfdbfffff,0xfdbf8000-0xfdbfbfff irq 18 at device 0.0 on pci2 re0: Using 1 MSI-X message re0: Chip rev. 0x2c800000 re0: MAC rev. 0x00100000 miibus0: <MII bus> on re0 rgephy0: <RTL8169S/8110S/8211 1000BASE-T media interface> PHY 1 on miibus0 rgephy0: none, 10baseT, 10baseT-FDX, 10baseT-FDX-flow, 100baseTX, 100baseTX-FDX, 100baseTX-FDX-flow, 1000baseT, 1000baseT-master, 1000baseT-FDX, 1000baseT-FDX-master, 1000baseT-FDX-flow, 1000baseT-FDX-flow-master, auto, auto-flow re0: Using defaults for TSO: 65518/35/2048 re0: Ethernet address: 1c:1b:0d:44:26:b5 re0: netmap queues/slots: TX 1/256, RX 1/256 ahci0: <AMD SB7x0/SB8x0/SB9x0 AHCI SATA controller> port 0xff00-0xff07,0xfe00-0xfe03,0xfd00-0xfd07,0xfc00-0xfc03,0xfb00-0xfb0f mem 0xfe02f000-0xfe02f3ff irq 22 at device 17.0 on pci0 ahci0: AHCI v1.10 with 4 3Gbps ports, Port Multiplier supported ahci0: quirks=0x22000<ATI_PMP_BUG,1MSI> ahcich0: <AHCI channel> at channel 0 on ahci0 ahcich1: <AHCI channel> at channel 1 on ahci0 ahcich2: <AHCI channel> at channel 2 on ahci0 ahcich3: <AHCI channel> at channel 3 on ahci0 ohci0: <AMD SB7x0/SB8x0/SB9x0 USB controller> mem 0xfe02e000-0xfe02efff irq 16 at device 18.0 on pci0 usbus0 on ohci0 ohci1: <AMD SB7x0/SB8x0/SB9x0 USB controller> mem 0xfe02d000-0xfe02dfff irq 16 at device 18.1 on pci0 usbus1 on ohci1 ehci0: <AMD SB7x0/SB8x0/SB9x0 USB 2.0 controller> mem 0xfe02c000-0xfe02c0ff irq 17 at device 18.2 on pci0 usbus2: EHCI version 1.0 usbus2 on ehci0 ohci2: <AMD SB7x0/SB8x0/SB9x0 USB controller> mem 0xfe02b000-0xfe02bfff irq 18 at device 19.0 on pci0 usbus3 on ohci2 ohci3: <AMD SB7x0/SB8x0/SB9x0 USB controller> mem 0xfe02a000-0xfe02afff irq 18 at device 19.1 on pci0 usbus4 on ohci3 ehci1: <AMD SB7x0/SB8x0/SB9x0 USB 2.0 controller> mem 0xfe029000-0xfe0290ff irq 19 at device 19.2 on pci0 usbus5: EHCI version 1.0 usbus5 on ehci1 atapci0: <ATI IXP700/800 UDMA133 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xfa00-0xfa0f at device 20.1 on pci0 ata0: <ATA channel> at channel 0 on atapci0 ata1: <ATA channel> at channel 1 on atapci0 hdac1: <ATI SB600 HDA Controller> mem 0xfe024000-0xfe027fff irq 16 at device 20.2 on pci0 isab0: <PCI-ISA bridge> at device 20.3 on pci0 isa0: <ISA bus> on isab0 pcib3: <ACPI PCI-PCI bridge> at device 20.4 on pci0 pci3: <ACPI PCI bus> on pcib3 ohci4: <AMD SB7x0/SB8x0/SB9x0 USB controller> mem 0xfe028000-0xfe028fff irq 18 at device 20.5 on pci0 usbus6 on ohci4 uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0 atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0 atkbd0: <AT Keyboard> irq 1 on atkbdc0 kbd0 at atkbd0 atkbd0: [GIANT-LOCKED] ppc0: cannot reserve I/O port range hwpstate0: <Cool`n'Quiet 2.0> on cpu0 Timecounters tick every 1.000 msec nvme cam probe device init hdacc0: <ATI R6xx HDA CODEC> at cad 0 on hdac0 hdaa0: <ATI R6xx Audio Function Group> at nid 1 on hdacc0 pcm0: <ATI R6xx (HDMI)> at nid 3 on hdaa0 pcm1: <ATI R6xx (HDMI)> at nid 5 on hdaa0 hdacc1: <Realtek ALC887 HDA CODEC> at cad 0 on hdac1 hdaa1: <Realtek ALC887 Audio Function Group> at nid 1 on hdacc1 pcm2: <Realtek ALC887 (Rear Analog)> at nid 20 and 24,26 on hdaa1 pcm3: <Realtek ALC887 (Front Analog)> at nid 27 and 25 on hdaa1 usbus0: 12Mbps Full Speed USB v1.0 usbus1: 12Mbps Full Speed USB v1.0 usbus2: 480Mbps High Speed USB v2.0 usbus3: 12Mbps Full Speed USB v1.0 usbus4: 12Mbps Full Speed USB v1.0 usbus5: 480Mbps High Speed USB v2.0 usbus6: 12Mbps Full Speed USB v1.0 ugen0.1: <ATI> at usbus0 uhub0: <ATI OHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus0 ugen1.1: <ATI> at usbus1 uhub1: <ATI OHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus1 ugen2.1: <ATI> at usbus2 uhub2: <ATI EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus2 ugen3.1: <ATI> at usbus3 uhub3: <ATI OHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus3 ugen4.1: <ATI> at usbus4 uhub4: <ATI OHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus4 ugen5.1: <ATI> at usbus5 uhub5: <ATI EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus5 ugen6.1: <ATI> at usbus6 uhub6: <ATI OHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus6 uhub6: 2 ports with 2 removable, self powered uhub0: 3 ports with 3 removable, self powered uhub1: 3 ports with 3 removable, self powered uhub3: 3 ports with 3 removable, self powered uhub4: 3 ports with 3 removable, self powered uhub2: 6 ports with 6 removable, self powered uhub5: 6 ports with 6 removable, self powered ada0 at ahcich0 bus 0 scbus0 target 0 lun 0 ada0: <TOSHIBA DT01ACA100 MS2OA750> ATA8-ACS SATA 3.x device ada0: Serial Number 86IKWR6NS ada0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes) ada0: Command Queueing enabled ada0: 953869MB (1953525168 512 byte sectors) SMP: AP CPU #1 Launched! SMP: AP CPU #3 Launched! SMP: AP CPU #2 Launched! Timecounter "TSC-low" frequency 1908478009 Hz quality 1000 Trying to mount root from ufs:/dev/ufs/FreeBSD_Install [ro,noatime]... Root mount waiting for: usbus5 ugen5.2: <SanDisk> at usbus5 umass0: <SanDisk Ultra, class 0/0, rev 2.10/1.00, addr 2> on usbus5 umass0: SCSI over Bulk-Only; quirks = 0x8100 umass0:6:0: Attached to scbus6 da0 at umass-sim0 bus 0 scbus6 target 0 lun 0 da0: <SanDisk Ultra 1.00> Removable Direct Access SPC-4 SCSI device da0: Serial Number 4C531001470902104180 da0: 40.000MB/s transfers da0: 14875MB (30464000 512 byte sectors) da0: quirks=0x2<NO_6_BYTE> GEOM: da0: the secondary GPT header is not in the last LBA. GEOM: diskid/DISK-4C531001470902104180: the secondary GPT header is not in the last LBA. mountroot: waiting for device /dev/ufs/FreeBSD_Install... ugen4.2: <SEM> at usbus4 ukbd0: <SEM USB Keyboard, class 0/0, rev 1.10/1.10, addr 2> on usbus4 kbd2 at ukbd0 GEOM: diskid/DISK-4C531001470902104180: the secondary GPT header is not in the last LBA. random: unblocking device. ugen4.3: <PixArt> at usbus4 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 ukbd1: <PixArt Gaming Mouse, class 0/0, rev 2.00/1.00, addr 3> on usbus4 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 hid_get_item: Number of items(324) truncated to 255 kbd3 at ukbd1 re0: link state changed to UP uhid0: <SEM USB Keyboard, class 0/0, rev 1.10/1.10, addr 2> on usbus4 ums0: <PixArt Gaming Mouse, class 0/0, rev 2.00/1.00, addr 3> on usbus4 ums0: 5 buttons and [XYZ] coordinates ID=0 re0: link state changed to DOWN re0: link state changed to UP
