[syslinux] Unable to write mbr using syslinux.exe

Gene Cumm gene.cumm at gmail.com
Mon Sep 5 04:02:38 PDT 2011

On Mon, Sep 5, 2011 at 01:32, asha sathurappan <asha.here at yahoo.com> wrote:
> Hi,
> I tried to use the syslinux.exe (version 4.04) to make my usb drive bootable. When i run the syslinux.exe with the respective options I get this error
> "Accessing physical drive: The request is not supported. Did not successfully update the MBR; continuing..."
> I have administrator privilege and I started cmd prompt with "Run as Administrator" option too. I tried the win64 syslinux version. I tried formatting my usb drive. I also tired with different usb flash drives (new ones). I also tried to disable the UAC in windows 7.  I still get the error.

I think you did a good job of testing to get around the common Windows
protections.  Seeing as you have a 64-bit version of Windows, I'd
expect win64/syslinux64.exe should be better than win32/syslinux.exe.
UAC will only prevent an application that performs privileged
operations from running.

Have you tried booting any of these UFDs after seeing this error?
It's possible their MBRs were preconfigured.

> System Properties:
> Notebook model: Lenova T410
> Operating system: Windows 7 Professional SP1 64-bit
> Processor: Intel(R) Core(TM) i5 CPU
> RAM: 4GB
> BIOS version/date: Lenova 6IET74WW(1.34),10/25/2010
> SMBIOS version: 2.6

Could it be possible that you have anti-virus software that prevents
applications from writing to any MBR?  This is a common protection.
If this is the case, you'd normally want it on to protect against
other rogue applications.  Whitelisting syslinux64.exe or temporarily
disabling this should work.


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