New motherboard boots straight into BIOS instead of Windows
Asked by
MellowPine47
I installed a new ASUS TUF B760 motherboard with my existing CPU, RAM, and SATA SSD. The BIOS detects the CPU, memory, and drive, but it says there is no bootable device and never starts Windows. The SSD previously booted Windows normally in my old system. Is there a BIOS setting I need to change, or do I need to reinstall or reconfigure Windows for the new motherboard?
Answers
First confirm that the SSD is actually visible in the BIOS. Since it uses a SATA cable rather than an M.2 slot, check both the SATA data connection and power cable, and try another SATA port or cable if necessary. If the drive is detected but no Windows Boot Manager appears, the issue is probably the boot mode rather than the drive itself.
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Your previous Windows installation may have been set up using legacy BIOS/MBR, while the new board is set to UEFI by default. In the firmware settings, look for CSM or Legacy Boot and temporarily enable it. That may allow the existing installation to start. The better long-term fix is to convert the system disk from MBR to GPT, if possible, then boot in UEFI mode again. Back up important files before changing partitions or reinstalling anything.
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In the boot settings, the first boot option should be Windows Boot Manager on that SSD, not just the bare drive name. If the boot priorities are unavailable or greyed out, the firmware may not recognize a valid bootloader. You can repair the bootloader using Windows installation media, but changing from legacy mode to UEFI or reinstalling Windows may still be necessary.
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Moving an existing Windows installation to a different motherboard can also require chipset and storage-driver changes, and Windows activation may need to be re-established. However, those usually matter after the system begins booting; a 'no bootable device' message points first to the SSD connection, boot mode, or missing Windows Boot Manager.
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QuietRaven31: If conversion is not practical, a clean Windows installation in UEFI mode is usually the most reliable option. Make sure the installer USB is created for UEFI and select the SSD as the installation target.