Problem with downgrade to Win7x64Pro on GPT disc

At the earliest sorry for my bad english, I'm from Czech.

I want to downgrade my ASUS X55A to Windows7 x64 Pro, but during install come the error:



I used this tuto: UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with
I used Rufus to prepare bootable USB (but compared to tutorial is my version 1.3.4.270, and there is not GPT Partititon Scheme in Partition Scheme Option. So I used MBR Partition Scheme for UEFI computers).
I want install in UEFI mode, not in BIOS Mode.
Secure Boot is disabled. Fast Boot is disabled.

I read about bdcedit function on command line, I can run it, but I cannot work with it. Just this:



Thank you for all answers.

Is this a OEM manufacturer's PC with Pre-installed Windows 8?

1) Downgrade to Windows 7.
Downgrade Windows 8 to Windows 7
Warning you must have the UEFI/BIOS firmware setting in Step Three set.

Make sure you read the NOTE at Step three.

2) If Using a USB Pen drive on a PC with a UEFI BIOS.
USB Pen drive need to be formatted to FAT32 as in
UEFI Bootable USB Flash Drive - Create in Windows
Take note of Step 11 for Windows 7.
Also you will need to use a USB 2.0 port, as there are no USB 3.0 drivers in Windows 7.


You will need to buy Windows 7.

Uuuuf. All was right, just CSM wasn't enabled. Now is install done. Thank you for all. Have a nice days.

marrier said:

Uuuuf. All was right, just CSM wasn't enabled. Now is install done. Thank you for all. Have a nice days.

Hi there.

Glad you got your problem solved - but just curious :

What's CSM. Another poster recently said the same thing about enabling CSM -- so if this is a decent solution what's CSM. I asked the same question to that poster but never did get an answer back.

Cheers
jimbo

What's CSM. Another poster recently said the same thing about enabling CSM -- so if this is a decent solution what's CSM. I asked the same question to that poster but never did get an answer back.

Nice small video here:

For more info on uEFI:
Windows and GPT FAQ
Unified Extensible Firmware Interface - Wikipedia, the free encyclopedia
UEFI Firmware
Technical Note: UEFI BIOS vs. Legacy BIOS, Advantech(EN) - YouTube
Sample: Configure UEFI/GPT-Based Hard Drive Partitions by Using Windows PE and DiskPart

CSM = Compatibility Support Module

http://en.wikipedia.org/wiki/Unified...ware_Interface

CSM booting

For backwards compatibility, most of the UEFI implementations on PC-class machines also support booting in legacy BIOS mode from MBR-partitioned disks, through the Compatibility Support Module (CSM) which provides legacy BIOS compatibility. In that scenario, booting is performed in the same way as on legacy BIOS-based systems, by ignoring the partition table and relying on the content of a boot sector.[28]

BIOS booting from MBR-partitioned disks is commonly called BIOS-MBR, regardless of it being performed on UEFI or legacy BIOS-based systems. As a side note, booting legacy BIOS-based systems from GPT disks is also possible, and it is commonly called BIOS-GPT.

Despite the fact MBR partition tables are required to be fully supported within the UEFI specification,[33] some UEFI firmwares immediately switch to the BIOS-based CSM booting depending on the type of boot disk's partition table, thus preventing UEFI booting to be performed from EFI System partitions on MBR-partitioned disks.[28] Such a scheme is commonly called UEFI-MBR.

I thought CSM will install just in BIOS mode, but it's not that.

ASUS are pre-set to UEFI & Legacy mode.