I Can't Convert MBR to GPT on HPE Proliant SE1220, Help Please

I have an HPE ProLiant SE1220 server. I created a new raid storage, and now the server has more than 9TB, but when I try to install the Windows Server after installation, only 2TB is available (the rest is unusable unallocated storage), and all drives are MBR. I need to convert it to GPT to use all 9TB. My question is, how to do it?

You cannot install the system drive, which contains Windows, as GPT on an older server. Why not simply set up 2 virtual disks on your underlying storage? Hence, there will be one virtual drive for the system that is, say, 200GB or whatever (Windows will subsequently place C: on this drive, and it will be bootable and formatted as MBR), and another drive for data or virtual machines or whatever else will take up the remaining space.

You can use the entire space if you initialize this second virtual drive as GPT in Disk Management after installing Windows.

But if you are not a professional, EaseUS Partition Master Server may be a better choice. This tool allows you to convert MBR to GPT with three simple clicks. This tool supports Windows 11/10/8/7/XP and Windows Vista.

Here is how to use EaseUS Partition Master to convert MBR to GPT:

Step 1: Download EaseUS Partition Master to your computer and run it. Visit the Disk Converter section next.

Step 2: Choose "Convert GPT to MBR" and press "Next" to proceed.

Step 3: Choose the GPT disk that needs to be changed to MBR, then click "Convert" to begin the process.