F5F Stay Refreshed Hardware Desktop Issues with PC startup after changing to UEFI?

Issues with PC startup after changing to UEFI?

Issues with PC startup after changing to UEFI?

M
Mikayuu_
Member
182
01-27-2026, 12:44 AM
#1
I changed from MBR to GPT, then from CSM to UEFI. Now whenever I attempt to boot, I encounter a black screen with lines at the bottom, followed by a blank blue screen, and the computer stops working shortly afterward. It doesn’t work even when I switch back to CSM; the lines appear only on the right side of the screen in that case.

I’m using Windows 10 and here are my specifications:
CPU: AMD Ryzen 7 2700X (8 cores / 16 threads)
GPU: NVIDIA GeForce RTX 2060 Super 8GB
RAM: 16GB DDR4
Storage: 500GB SATA SSD
Motherboard: AM4 Micro-ATX (B450)
Power Supply: 550W
M
Mikayuu_
01-27-2026, 12:44 AM #1

I changed from MBR to GPT, then from CSM to UEFI. Now whenever I attempt to boot, I encounter a black screen with lines at the bottom, followed by a blank blue screen, and the computer stops working shortly afterward. It doesn’t work even when I switch back to CSM; the lines appear only on the right side of the screen in that case.

I’m using Windows 10 and here are my specifications:
CPU: AMD Ryzen 7 2700X (8 cores / 16 threads)
GPU: NVIDIA GeForce RTX 2060 Super 8GB
RAM: 16GB DDR4
Storage: 500GB SATA SSD
Motherboard: AM4 Micro-ATX (B450)
Power Supply: 550W

C
Courenses69
Junior Member
48
01-27-2026, 12:44 AM
#2
Welcome to the forums, newcomer! I changed from MBR to GPT. Could you explain the process for converting the drive's partition style? Motherboard: AM4 Micro-ATX (B450). The B450 chipset—what is your motherboard model and BIOS version? Power Supply: 550W. The PSU details? It doesn’t work even when I switch back to csm; the lines appear on the right side of the blue screen. Can’t get into Safe Mode?
C
Courenses69
01-27-2026, 12:44 AM #2

Welcome to the forums, newcomer! I changed from MBR to GPT. Could you explain the process for converting the drive's partition style? Motherboard: AM4 Micro-ATX (B450). The B450 chipset—what is your motherboard model and BIOS version? Power Supply: 550W. The PSU details? It doesn’t work even when I switch back to csm; the lines appear on the right side of the blue screen. Can’t get into Safe Mode?

Z
zimmion
Junior Member
15
01-27-2026, 12:44 AM
#3
Corrected the issue by observing a black screen with white lines, followed by a blue screen displaying vertical lines on the right before shutdown. Used the validate prompt in the Command Prompt and applied the mbr2gpt /convert /allowFullOS command. The process completed successfully. Adjusted the BIOS to UEFI and disabled all legacy and CSM settings.
Z
zimmion
01-27-2026, 12:44 AM #3

Corrected the issue by observing a black screen with white lines, followed by a blue screen displaying vertical lines on the right before shutdown. Used the validate prompt in the Command Prompt and applied the mbr2gpt /convert /allowFullOS command. The process completed successfully. Adjusted the BIOS to UEFI and disabled all legacy and CSM settings.