How Can I Solve Non System Disk or Disk Error, I Need Help

I recently got a problem and it almost drove me crazy. I replaced HDD with SSD in many computers, and since then, I have always gotten 'Non-system disk or disk error,' which affected my daily work a lot. Please assist me in solving this issue.

If the system is expecting UEFI and you have provided the Legacy/BIOS, you receive that error. Or if the system is expecting BIOS, you will receive this error if you provide UEFI. Hence, you need to convert MBR to GPT or GPT to MBR. The detail is as follows:

• MBR: BIOS
• GPT: UEFI

If you are confused and don't know which one to choose, the following details can help:

GPT: it allows users to create 128 primary partitions, and each one can be larger than 2TB.

MBR: It only allows users to create four primary partitions, and each one can't be larger than 2TB.

So you can choose MBR or GPT if your partition is smaller than 2T and choose GPT only if the partition is larger than 2TB. After figuring out which one to choose, you can start to convert. As for this point, I strongly recommend you choose a trustworthy too, such as EaseUS Partition Master.

This tool is an all-in-one disk utility with a clear interface. Next, I'll show you how to use it to convert MBR to GPT:

Step 1. Click open EaseUS Partition Master and navigate to "Disk Converter" on the left panel.

Step 2. Choose "Convert MBR to GPT" and click "Next." (You can also choose "Convert GPT to MBR" at this step.)

Step 3. Select the target MBR/GPT disk and click "Convert."