The BIOS and UEFI are both small programs stored on a chip of your computer’s motherboard that allow the data flow between the operating system (like Windows or Linux) and the other connected hardware like the disks, printers, keyboard, mouse, graphics cards, network and so on. BIOS was more popular in older computers and it is now being replaced with UEFI. In fact, if you buy a new computer or a new motherboard than it would come with UEFI instead of the older BIOS. With the UEFI, a new type of disk partitions called GUID partition table (or GPT in short) are possible. UEFI allows both the MBR and GPT partitions for your disks.
Here is how you can find out which type of partition style your disks have in Windows :
- Press the key combination Win+R to open the Run dialog. Type diskmgmt.msc in the Run dialog and press Enter.
- In the Disk Management window, all the connected disks would be labeled as Disk 0, Disk 1, Disk 2 and so on. Select the disk you want to find about, right-click on it and then choose Properties from the right-click menu.
- In the Disk Device Properties window, switch to the Volume tab. Here you can see the Partition style for the selected disk. It would be either Master Boot Record (MBR) type or the GUID Partition Table (GPT) style.
There is another quicker way to find the same information, but using some command-line interface tools:
- Launch elevated command prompt. For this, you can press the Win+X key combination and select Command Prompt (Admin) from the menu that appears.
- Then give these commands one after another:
diskpart
list disk
exit - You can see the disks attached in your PC labeled as Disk 0, Disk 1 and so on. Against each of these disks, you will see some information. If the disk is partitioned in GPT style, then you will see an asterisk (*) for the GPT column for that disk. If the disk is partitioned in MBR style, then you will see nothing in the GPT column.
Conclusion: Finding whether your disk is partitioned GPT or MBR way is very important when you are installing Windows on it. If your UEFI is configured properly and your disk is GPT partitioned, then Windows may refuse to install on that disk.