Unable to load Windows from an M.2 SSD? This guide from MiniTool Partition Wizard explains the most common causes, including incorrect UEFI/BIOS settings and boot order issues, and provides step-by-step fixes to get your system running again. You’ll also learn how to recover data if your PC won’t boot after installing an M.2 SSD.
Unable to load Windows from an M.2 SSD? This guide explains the common causes and effective fixes to help Windows 10/11 boot from your M.2 SSD again.
Why Won’t Windows Boot from an M.2 SSD? Common Causes and Fixes
Windows may fail to boot from an M.2 SSD due to incorrect BIOS settings, motherboard compatibility issues, etc. The table below lists the most common causes and their solutions.
| Cause | Why It Happens | Fix |
| Wrong BIOS Boot Mode | System uses Legacy/CSM instead of UEFI, which M.2 SSDs require | Disable CSM and enable UEFI mode in BIOS |
| MBR Instead of GPT | The SSD uses an incompatible partition style for UEFI boot | Convert MBR to GPT or reinstall Windows using GPT |
| M.2 Shared Lane Conflict | The M.2 slot disables certain SATA ports on some motherboards | Change SATA ports or use another M.2 slot |
| Boot Files Installed on Another Drive | Windows puts boot files on an old connected drive during installation | Disconnect other drives and reinstall Windows on the M.2 SSD |
After identifying the possible cause, you can try the following solutions to fix the M.2 SSD boot issue. Start with the simplest fixes and move to more advanced troubleshooting methods if needed.
How to Fix Unable to Load Windows from M.2 SSD
If Windows not booting after installing M.2 SSD, the first step is to identify whether the issue comes from the SSD, BIOS settings, or Windows boot files.
Below are several proven fixes to help you troubleshoot and repair the M.2 SSD boot problem.
Fix 1. Disconnect Any Other Storage Drive on Your PC
When Windows won’t boot from an M.2 SSD, other connected storage drives may cause boot conflicts or prevent the system from selecting the correct boot device. Disconnect all other storage drives, leaving only the M.2 SSD connected, and then restart your computer.
If Windows boots successfully, reconnect the other drives one at a time to identify the drive causing the conflict.
Fix 2: Reseat the M.2 SSD
A loose or improperly installed M.2 SSD may prevent your computer from detecting the drive or booting Windows correctly.
Turn off your PC, remove the M.2 SSD, clean any dust from the connector and slot, and then firmly reinsert the SSD into the slot before securing it with the mounting screw. After that, restart your computer and check whether Windows boots normally.
Fix 3: Check and Change M.2 SSD Boot Priority in BIOS
Sometimes, you are unable to boot Windows from M.2 SSD simply because your computer is trying to start from another drive.
In this case, you need to change the boot priority in the BIOS and set the Windows Boot Manager on your M.2 SSD as the first boot device.
Here are the steps:
- Restart your computer and press the BIOS key (such as F2, F10, F12) repeatedly to enter BIOS settings.
- Go to the Boot menu and select the M.2 SSD to the top of the boot list.
- Save the changes and restart your computer.
If Windows still cannot boot from the M.2 SSD after changing the boot order, try the following methods.
Fix 4. Disable the CSM Module
CSM is short for Compatibility Support Module, which is a part of some UEFI firmware implementations. It provides legacy BIOS compatibility by emulating a BIOS environment, allowing legacy operating systems and some option ROMs that do not support UEFI to still be used.
Well then, how to disable CSM in BIOS? Now, let’s see the detailed steps.
Step 1. Enter the BIOS setting on your PC. The key to enter BIOS varies from PC to PC. It depends on your PC’s manufacturer and model.
Step 2. Locate to the Boot section.
Step 3. Depending on the model of your PC or laptop and the EFI firmware, the setting to change CSM can be different. Notice the possible setting names. Turn it off or disable it.
- Legacy Support
- Boot Device Control
- Legacy CSM
- Launch CSM
- CSM
- UEFI/Legacy Boot (set to UEFI Only)
- Boot Mode (set to No Legacy Support)
- Boot Option Filter (set to UEFI Only)
- UEFI/Legacy Boot Priority (set to UEFI Only)
Step 4. Save the change and exit the BIOS setting.
When you encounter the Windows not booting after installing M.2 SSD issue, you may try this way to get rid of the problem.
Fix 5. Update BIOS
Another reason for M.2 SSD not booting is that the motherboard of your computer is not updated to be able to recognize to boot from M.2 SSD. In this case, your PC won’t boot after installing M.2 SSD.
So, always make sure you have the latest revision of BIOS installed on your PC. You can go to the manufacturer’s website to get the latest BIOS update (.cap file) or check out the user manual to find out the way to update your computer’s BIOS.
Install the update from BIOS and reboot. Then the M.2 SSD should be able to be boot you’re your Windows PC.
Fix 6. Change the SATA Port
According to a forum user report, plugging into the incorrect port may cause the inability to load Windows from M.2 SSD.
Certain SATA ports on motherboards share bandwidth with M.2 slots, meaning plugging a SATA cable into specific ports can disable the NVMe SSD, causing it to not be detected during Windows installation.
To fix this, change the SATA port used or set the BIOS storage mode to AHCI.
To set the BIOS storage mode to AHCI, restart your computer and enter the BIOS setup. Navigate to Advanced or Storage Configuration, find the SATA Mode or Configure SATA as option, change it to AHCI, save changes, and exit.
How to Recover Data from an Unbootable M.2 SSD
If Windows won’t boot from M.2 SSD, recover important files before attempting advanced repairs or reinstalling Windows.
MiniTool Partition Wizard can help you recover documents, photos, videos, and other files from an unbootable computer.
Follow the steps below to retrieve your data safely.
MiniTool Partition Wizard DemoClick to Download100%Clean & Safe
Step 1. Get MiniTool Partition Wizard Pro Ultimate by clicking the following button. Install it on a normal computer.
Step 2. Create a bootable USB drive with the Bootable Media feature embedded in this software.
Step 3. Connect the bootable drive you’ve made to the computer with the M.2 not booting.
Step 4. Enter the BIOS settings menu and change the boot order to boot from the USB drive.
Step 5. When you get the interface of MiniTool Partition Wizard, launch the Data Recovery wizard.
Step 6. On the Data Recovery interface, select the partition that contains important files on it and click Scan.
Here Data Recovery will list 5 parts, and every part is different from each other.
- Recovery Result: this part shows the last scanning result record.
- Logical Drive: this part shows all existing partitions on your computer.
- Lost Partition: this part shows all lost partitions on your PC.
- Unallocated Space: this part shows all unallocated spaces on your computer.
- Hard Disk: this part lists all hard disks on the computer. You can also select a hard disk to scan.
Step 8. The software is scanning your drive now. During the process, you can pause or stop the scanning by clicking the Pause or Stop button near the progress bar if you find the files you need.
Step 9. Check items you need from the recovery result and click Save button.
To find needed files quickly, you can utilize the following three tools
- Show lost file: by utilizing this feature, you can only see the lost files on the recovery result.
- Find: With the Find tool, you can search a specific file by matching case or matching word.
- Filter: You can search for files by their filename/extension, file size, creation or modification date with this function.
Step 10. Choose a directory to save needed files. It is recommended to save the recovered files on another drive. Otherwise, the lost/deleted data could be overwritten.
This is how to get files off an M.2 SSD not booting with MiniTool Partition Wizard Pro Ultimate. If you want to access important files immediately, try this way.
Bottom Line
Hopefully, this guide has helped you understand why Windows may fail to boot from an M.2 SSD and provided effective solutions to fix the issue. By checking BIOS settings and ensuring proper SSD configuration, you should be able to get Windows running from your M.2 SSD again.
If you need any help when using MiniTool software, you can contact us via [email protected].
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