I built a new PC with a Ryzen 5 9600X, RTX 5060 Ti, and an MSI B650-S WiFi motherboard. The system enters BIOS normally, and both the HDD and SSD are detected. However, when I connect the external USB-C drive containing my Windows installation files, the computer does not start Windows Setup. It repeatedly powers up, briefly shows the MSI logo with keyboard input working, then loses input and restarts the cycle. The BIOS detects the external drive, although it labels it as a hard disk. I created the installer with Rufus and tried different FAT32/GPT configurations. The hardware seems functional, so could the installation media or boot configuration be causing this reboot loop?
3 Answers
The external drive may not have been made truly bootable, even if the BIOS can detect it as storage. Recreate the installer from a Windows ISO using the official Windows Media Creation Tool, preferably on a regular USB flash drive rather than an external hard drive. Then use the motherboard's one-time boot menu to select the USB's UEFI entry.
Make sure the motherboard firmware supports the Ryzen 5 9600X. Depending on when the board was manufactured, it may need a BIOS update before everything works reliably. Download the correct BIOS for the exact MSI model and follow MSI’s update instructions, using the board’s flashback feature if available.
Once the installation USB is created correctly, disconnect the extra HDD temporarily and leave only the target SSD connected. Enter BIOS, confirm UEFI boot mode, disable any legacy or CSM mode if enabled, and choose the USB installer from the boot menu. After Windows Setup starts, install to the SSD and reconnect the other drive afterward. Back up anything important before changing partitions or performing a clean installation.
I was using Rufus and tried FAT32 with GPT, but I’ll recreate the installer on a standard USB drive and select its UEFI boot option directly.