Windows: UEFI o legacy (BIOS)

Summary

In this video, Pol Padrisa from SYSADMIT explains the differences between UEFI and BIOS, highlighting UEFI's advantages like faster boot times, support for 64-bit OS, and more than four primary partitions. He also discusses the dangers of switching between UEFI and BIOS modes, which can lead to data loss and OS boot issues. Padrisa provides methods to determine if a system is using UEFI or BIOS, including checking system information, disk management, and Panther logs, emphasizing the importance of this knowledge for troubleshooting and system maintenance.

Takeaways

• 💻 UEFI (Unified Extensible Firmware Interface) is meant to replace the older BIOS (Basic Input Output System), offering new functionalities.
• 🚀 UEFI booting is faster than BIOS, improving overall system performance.
• 🖥️ UEFI only supports 64-bit operating systems, while BIOS can handle 32-bit systems.
• 📦 UEFI allows more than four primary partitions per unit, overcoming the limitations of BIOS.
• 📏 UEFI supports system drives larger than 2TB by using GPT (GUID Partition Table) instead of MBR (Master Boot Record).
• 🔒 UEFI provides more security by protecting the pre-OS boot process.
• ⚠️ Switching between UEFI and BIOS requires reinstalling the operating system and causes data loss.
• 🔍 It's important to know whether your system is using UEFI or BIOS to prevent issues like boot failure or hardware configuration problems.
• 🛠️ Method 1: You can check if your system uses UEFI or BIOS by running `msinfo32.exe` and looking for the BIOS Mode.
• 💾 Method 2: In `diskmgmt.msc`, if your system disk has three partitions (EFI system, Microsoft reserved, and NTFS for Windows), it’s UEFI. Fewer partitions mean it’s BIOS.

Q & A

What is UEFI?

UEFI stands for Unified Extensible Firmware Interface, which is designed to replace the older BIOS (Basic Input Output System), adding new functionalities.

What are the benefits that UEFI brings compared to BIOS?

UEFI offers faster boot times, supports only 64-bit operating systems, allows more than four primary partitions per disk, enables the use of volumes larger than 2TB with GPT (GUID Partition Table) instead of MBR (Master Boot Record), requires a UEFI boot partition, and provides enhanced security by protecting the pre-boot process.

What are the potential dangers of switching from BIOS to UEFI or vice versa?

Switching between UEFI and BIOS modes may require reinstalling the operating system and can result in data loss on the disk.

Why is it important to know whether a system is running on UEFI or BIOS?

Knowing whether a system is running on UEFI or BIOS is crucial for troubleshooting issues like boot failures that can occur if the firmware configuration changes from UEFI to BIOS or due to hardware replacements that alter the system's boot mode.

How can you determine if a Windows system is installed in UEFI or BIOS mode?

There are several methods to determine the boot mode: 1) System Information via msinfo32.exe, 2) Disk Management via diskmgmt.msc, and 3) Checking logs in the Panther directory.

What does the System Information tool (msinfo32.exe) reveal about the BIOS mode?

The System Information tool shows 'Legacy' if Windows was installed in BIOS mode and 'UEFI' if it was installed in UEFI mode under the 'BIOS Mode' section.

How can the Disk Management tool (diskmgmt.msc) help identify the boot mode?

Disk Management shows the partition types and formats. If there are three primary partitions with formats FAT32 for EFI System Partition, no format for Microsoft reserved partition, and NTFS for the Windows installation partition, it indicates UEFI mode. One or two primary NTFS partitions suggest BIOS mode.

What information can be found in the Panther directory regarding the installation mode?

The Panther directory, found at C:\Windows\Panther, contains logs that can be checked to determine if Windows was installed in UEFI or BIOS mode, even when done offline.

What are the implications of changing the boot mode on a system with a default UEFI configuration?

Changing the boot mode from UEFI to BIOS or vice versa can cause the operating system to fail to boot, necessitating a reinstallation and leading to data loss.

Can you provide an example of why it's important to know the boot mode when replacing a motherboard?

If a desktop with a default UEFI configuration has its motherboard replaced with one set to Legacy (BIOS) mode, and the firmware configuration is not adjusted, Windows may fail to boot after the replacement.