Win7 does not boot after BIOS update - dual boot

Check your Sata settings, if you updated the bios it generally resets to factory defaults, if you installed with ACHI mode and then it reset back to ide or other modes it wont function. Check out these settings and let us know.

That was my first thought also. If Windows 7 was installed with the BIOS set to IDE or ACHI you need to make sure it put back to that mode.

So the first thing I would do is go to the BIOS and change it to the opposite of what it is now and see if Windows 7 will boot then.

Well if you weren't raiding then try the only other one in the list lol

When the computer boots up you should be able to hit F2(I think on a dell) to get into bios. As far as risk of data loss - you're ALWAYS at risk of a hard drive going bad. You should already have a backup so the risk is minimized. The instructions for updating the bios should have a step telling you to make a backup of your data because issues like yous happen.

Have you been able to get into your BIOS to check your system configuration settings?

The first thing you need to do is go into your BIOS and see if the update was successful. Press the power button and immediately start pressing the Delete button. Once you see the POST screen there should be a line at the bottom of the screen that says something along the lines of "Entering Setup". If Delete doesn't work then it should be the F2 key.

Once you are in BIOS look for the BIOS version and verify that it is the updated version. You may have had some problems if the BIOS update file you used was configured for Windows since you are running Linux. While you are at it, verify the system date and time are correct and manually update them in they are wrong.

After verifying the BIOS version, the easiest thing you can do next is go to the last page of your BIOS settings and select "Load Setup (or Optimized) Defaults". Then press F10 and select yes to save changes and exit.

If the system boots at this point then you should obviously be set. If you still have the same problem then turn the computer off and go into BIOS again.

At this point you should look for something marked "Storage" or "Hard drive" setting. It should have 2-4 selectable options from the following list:
■IDE
■Legacy
■AHCI
■RAID

If it is currently set to Legacy or IDE then switch it to RAID. If it is currently set to AHCI the switch it to Legacy or IDE. If the setting is currently RAID then you should definitely switch it to one of the other options.


If you still can't boot at this point then either your BIOS update ruined your motherboard or you need to rebuild your Linux configuration so it can correctly interface with your new BIOS. If the BIOS update simply failed then you may still be able to complete it by making a BIOS update boot disk (flash or floppy drive).


Without more detailed information from you there is no other aid we can provide. If you want to provide Some specifics like the model of laptop, version of BIOS you had and were upgrading to, Linux version/build, etc. then advice can be tailored much better to your specific situation.

Ok, so is this a link to your exact model? You can try entering your service tag on that site to verify what exact model it gives you.

As far as making changes in the BIOS affecting your dual-boot configuration, it shouldn't cause any issues. Your computer system BIOS is stored entirely on a small chip on the laptop's motherboard. modifying the BIOS will not make any changes to the hard drive or any of its partitions.

Now, it sounds to me like this describes your current system configuration:

Your laptop came with Windows 7 or 8 pre-installed. You divided the single installed hard drive into two partitions after initial setup and installed Linux on the new, blank partition to create a dual-boot configuration. Before you attempted the BIOS update, your computer would not immediately load a specific operating system, but would instead go to a screen asking your which operating system you wanted to load. You selected either the Windows OS or Linux and your computer would boot into the one you wanted.

Now, assuming this is correct, what exactly happens when you first turn on the computer at this point?

Ok. Given that information I would definitely recommend following my previous directions to enter and verify your your BIOS configuration settings. Give that a try and let me know what you find. Also, if you have difficulty navigating in the system BIOS then you write down some other information (menu options, etc.) available to you in the BIOS and post it here so I can provide more detailed/specific instructions.

Ok, first, as I mentioned earlier, the BIOS and all its settings are stored entirely on a small ROM chip on your motherboard. As such, none of the changes you make to it will have any affect whatsoever on the data stored on your hard drive. There are changes you can make that will modify the way that your hard drive and motherboard communicate, but at worst this will temporarily sever their ability to do so. The data on your hard drive, in both of your partitions will remain unchanged. From your earlier descriptions it sounds like you had to make a lot of configuration changes to your hard drive in order to get Linux up and running, so I can understand your concern. You can put those fears to rest, however, as the data on and configuration of your hard drive cannot and will not be changed by any modifications you make to your BIOS settings.

Second, when you ran the BIOS update, you performed the install from within Windows, correct?

Ok, the first thing I want you to do is correct the time error in your BIOS and try booting to Windows again. If it is more than just a couple minutes off then there is a chance that is the problem. Make sure the month, day, year, hour, and minute are correct then save and exit BIOS and try booting to Windows.

If that still doesn't work then load setup defaults and try again. If Windows still won't boot then check the storage setting I detailed above. Again, it should be in AHCI mode or, if there is no AHCI option, then IDE mode, but not RAID unless you have two or more drives and set them up in a RAID configuration when you first configured the laptop (highly unlikely).

Give it a try with the setup defaults. In an absolute worst case scenario it would change the storage interface setting and Linux might not boot, but this will not affect any of the data or software on your Linux partition. All that would be required to bring Linux back in this case is going back into BIOS and changing the storage setting back to what it was. BIOS settings cannot break Linux and create the need for a reinstall/reconfigure.

Excellent! I'm glad you hear you are back up and running, thought I'm very surprised that you aren't currently in AHCI mode with a Windows 7 computer. AHCI enables the full functionality of your SATA ports (options like hot-swapping).

Seeing how Linux was running fine with the BIOS setting on AHCI mode, I think you should be able to make the switch and simply need to re-install Windows 7 on its partition. If it were me I would do it (as I'm an IT guy and hate not having full functionality of my components due to a minor case of OCD). If you are feeling brave then you should be able to do it (again, without harming your Linux partition) after a simple backup if your Windows partition data.

If you don't feel like tackling that issue then I won't blame you, but if you do feel like giving it a go then I'd be happy to list out the steps I would recommend taking.