Package syslinux conflicts with syslinux-extlinux

[yaoyansi]

Hi all,
I installed CentOS7 x64 several days ago. Today, I'm trying to update software from "Applications>SystemTools>SoftwareUpdate", but it complains a conflict error. Here is log:

Test Transaction Errors: file /sbin/extlinux from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/cat.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/chain.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/cmd.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/config.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/cpuid.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux-extlinux-4.05-8.el7.x86_64
file /boot/extlinux/cpuidtest.c32 from install of syslinux-5.10-1.el7.rfx.x86_64 conflicts with file from package syslinux...

I not sure which package is installed in my system, syslinux or syslinux-extlinux. and I can't remember when and why it is installed.
What should I do now? Could you give me any help?

Cheers

[TrevorH]

Those packages with .rfx. in their names are from the rpmforge-extras repository. This is not a CentOS repo and is disabled by default when you install rpmforge-release. It contains packages that are known to conflict with CentOS packages. You'll need to downgrade the syslinux packages to get back to teh CentOS supplied ones

[yaoyansi]

Hi TrevorH,
Thanks for your reply.
I'm new to CentOS and linux, could you give me a step by step guide? Thank you in advance.

[TrevorH]

Just undo the change you already did to enable rpmforge-extras. Look in /etc/yum.repos.d for the right file and change enabled=1 to 0