There are many occasions when, for whatever reason, we leave a storage device connected to the PC when we turn it off, and when we turn it back on, the system refuses to boot until we unplug it. This occurs because the PC boot is configured to search for USB drives first , so in this article we are going to tell you what you should do to solve it.
As a general rule, even if you leave a USB storage drive connected to the PC when you turn it on (such as a pen drive or an external hard drive), the PC should not detect it as a boot device and therefore should not give an error when starting. the system. However, there are times when you have the device you have connected, if it is a storage device, the PC will believe that it is a boot drive and will give an error when it does not have an operating system installed on it.
Why do these problems happen?
There are certain conditions that must be met for the system to detect a USB storage drive as a bootable device, and this is precisely so to prevent the computer from trying to boot from it when you turn on the PC with a USB connected. In fact, despite the fact that in the boot configuration you have put the USB drives first before the system device on which you have the operating system installed, the PC should detect that there is no operating system installed on these drives and it will go to the next … however, there are times when this does not work as it should and that is when the problems come.
The error you receive when this happens should resemble the one in the image above, which tells us that an operating system has not been found and literally tells us to disconnect the device and press Ctrl + Alt + Del to restart the computer ( and try again).
This happens because despite not having an operating system installed on the USB drive, the system is detecting it as a boot device, and this is due to a bad configuration in the PC’s BIOS, so let’s see what we can do about it to fix it. You should also bear in mind that this only usually happens when your BIOS is set to Legacy mode, so setting the computer in UEFI mode will also solve the problem.
We have a complete tutorial to change the BIOS from Legacy to UEFI in case you prefer this alternative, which although it is more recommended than what we are going to tell you below, also requires a little more work and even involves some risks (this solution that we propose now it has no risk).
Disable USB boot
As we have said, this problem is caused by a bad configuration in the boot sequence in the BIOS, so of course it is in the BIOS where we have to apply the solution. To do this, restart the PC and look at the first screen that appears, where you should see a message similar to “Press DEL to enter Setup” or something similar. Depending on the manufacturer and the generation of your motherboard, it can be the DEL key, F2, F10 or F12, so just check which key you must press to enter the BIOS, restart the PC again and press it repeatedly to access is.
Once in the BIOS, again the thing depends on the manufacturer, model and generation of your motherboard, but as a general rule you should go to Advanced Settings, Advanced or something similar. On more modern motherboards you will see the “Boot” option directly in the upper right, and that is where you should go to change the configuration that interests us in order to solve this problem of booting from the USB.
Either way, you should find a setting called Boot Sequence, boot order, boot device or something similar – select that option and a menu will appear allowing you to select the boot devices that your motherboard supports. Depending on the BIOS, there are two alternatives here: different lines called “First Boot Device”, “Second Boot Device”, etc. appear. or the options appear directly.
The best thing you can do here is modify the boot sequence so that the first option is the storage unit (hard disk or SSD) where you have the operating system installed, and forget about all the other options. This, keep in mind, will disable the possibility of the computer booting directly from a USB drive when you need it and will limit itself to booting only from your normal storage unit, but it will undoubtedly solve the problem of the computer not booting when you have one. USB drive connected.
And what if you need to start the system from a USB?
If you already had the PC with the operating system active and running, normally you will never need to boot from a USB drive unless you intend to format the computer, reinstall Windows or you are forced to use a Live CD to solve problems; In any case, if you have previously disabled the option for the computer to boot from USB, don’t worry because it is obviously reversible.
All you have to do is access the BIOS again and follow the steps contrary to how we explained in the previous step, putting the USB devices as the first option in the boot sequence but without forgetting to put your normal storage unit as second option, since otherwise at the moment you take out the bootable USB, the system will not find your device to start normally.
As you can see, changing the startup sequence of your computer is something simple and it will not take you more than a minute once you know where the corresponding menu is to make the modification, so you do not have to be afraid when making these modifications every time you need it.