MSI X99S problem after bios upgrade

I recently got this board and after 2 weeks or so I upgraded it to a new bios version but it was not post, so I switched back to its previous bios version. Now the problem is that, after installing everything, the computer is not able to post into Windows. I did some testing and went back to defaults and then it started to post to windows. But when I turned on XMP for the RAM, I am only able to run 3 channels. I tried testing each stick at a time and they all worked with XMP enabled but with all 4 sticks installed it will not post to Windows. So, have you got any ideas how to fix this? Thanks

You can try to get the RAM working with XMP enabled by manually setting CL. You should also mail to MSI to let them know about the bad bios so that they can soon fix it and release a new one. If nothing is working then you can call MSI and ask them for a RMA to either get the board repaired or get a replacement board as well. Note that if there is any bent or boken pins then it will not be covered in the warranty.

I would suggest you to clear CMOS on your motherboard by taking out the battery for 5 seconds with the power cord unplugged. Also, you should try to boot without any usb devices. While installing the latest bios did you face any kind of interruption or the new bios got installed properly? I would suggest you to test your RAM with the memtest program and run each stick of RAM invidually and see if there are no errors produced.

I have heard that MSI X99S motherboard comes with dual bios so, try to switch to secondary bios and then try to boot and see if that works. If it is not getting to Windows then you should try to reinstall Windows and not BIOS because it might be corrupted. Try to test with only 1 RAM stick and take out the motherboard out of the case and put it on a non-conductive surface such as wooden table or motherboard box.