Hey there, let's clear up this confusion once and for all—this is a super common question when setting up Windows 10, so you're not alone!

先明确两个核心概念 #

First, let's define the two terms to avoid mix-ups:

安装模式 #

This refers to the firmware mode (UEFI or Legacy BIOS) your computer uses when you install Windows 10. For example:

• If you boot your installation USB in UEFI mode, Windows will automatically configure itself for UEFI: it'll use the GPT partition table, create an EFI System Partition (ESP), and install the UEFI-specific bootloader (bootmgfw.efi).
• If you boot the USB in Legacy mode, Windows will set up for Legacy BIOS: it'll use the MBR partition table, rely on the MBR boot sector, and install the Legacy bootloader (bootmgr).

运行模式 #

This is the firmware mode your computer uses every time it boots into the installed Windows 10 system. Normally, this matches the installation mode—but here's where the "difference" people talk about comes in.

安装模式与运行模式的具体差异 #

In most cases, you want these two modes to match, but there are scenarios where they don't (and this is usually not ideal):

• UEFI-installed system running in Legacy mode: Some motherboards have a Compatibility Support Module (CSM) that lets UEFI systems mimic Legacy BIOS behavior. If you install Windows 10 in UEFI mode (GPT partition), then later disable pure UEFI and enable CSM in your BIOS settings, the system might still boot—but you'll lose all UEFI advantages:

  • No fast boot or secure boot
  • Potential stability glitches (since Windows was configured for UEFI, not Legacy)
  • You're essentially forcing a square peg into a round hole here.

• Legacy-installed system running in UEFI mode: This is almost impossible. Legacy installs use MBR partitions, and most modern UEFI systems require GPT partitions to boot. Even if your motherboard allows it, the bootloader structures are completely incompatible (Legacy uses MBR boot sectors, UEFI uses ESP files), so the system won't start. You'd have to convert the partition table to GPT and reconfigure the bootloader, which is risky and not recommended.

为什么建议用UEFI模式安装Windows 10？ #

The advice to use UEFI isn't arbitrary—it's the modern standard for good reason:

• GPT partition support: Lets you use hard drives larger than 2TB, and offers more flexible partition management.
• Faster boot times: UEFI skips many of the slow hardware checks that Legacy BIOS performs, so your system starts up quicker.
• Security features: Secure Boot prevents malicious software from hijacking the boot process, which is a big win for system safety.
• Modern feature compatibility: Features like Windows Fast Startup, Windows Hello, and some virtualization tools rely on UEFI to work properly.

If your computer was made in the last 10 years, it almost certainly supports UEFI—just make sure to disable CSM in your BIOS settings before installing Windows to get the full UEFI experience.

内容的提问来源于stack exchange，提问作者SarpSTA