How to boot tablet from USB stick?

Question

I have Modecom Freetab 8025 tablet with Windows, and want to reinstall the OS. I connected a USB stick using a USB - micro USB cable. When starting the tablet, I can press the ESC key on the external keyboard, which gives me a menu (see #1, below).

In the boot manager, I have two choices (see #2, below).

The second option looks like #3, below.

The 6th option SCU in the ESC menu looks like #4, below.

I created a bootable USB with Rufus (see #5, below).:

How do I boot from USB? With Rufus, I tried all 3 options in the partition scheme and target system type.

Solution

In the EFI shell (image 3), you can use commands to locate the boot loader on the external USB drive, but it's going to take some poking around.

• Type fs0: to access the first filesystem, fs1: to access the second filesystem, and so on. Chances are there will be one filesystem (the EFI System Partition, or ESP) on the internal disk and at least one on the USB drive. (EFIs can read FAT, but not normally NTFS, so you won't be able to access your main Windows partition this way.)
• Type ls to view the files on the disk. An ESP normally has a directory called EFI, and there may be one or more other files or directories. The internal disk probably has an EFI\Microsoft directory and an EFI\BOOT directory. The external disk should have an EFI\BOOT directory, and might or might not have an EFI\Microsoft directory. The external disk might have files or directories associated with the installer; it depends on how Rufus set it up.
• Type cd to change into a directory, as in cd EFI\BOOT to change into EFI\BOOT on the current filesystem.
• Type the name of the boot loader you want to launch. On the external disk, this should be EFI\BOOT\bootia32.efi. (If you cd into EFI\BOOT, you'd type just bootia32.efi to launch it.) See below for a caveat, though....

You may want to familiarize yourself with what's on the USB disk in a fully-functioning computer so that you can more easily identify it in the EFI shell.

One more point: I just checked the specs, and your tablet has an Intel Atom CPU. I don't see anything explicit about this on the manufacturer's site, but most Atom-based tablets have 32-bit UEFIs. This means you can install only a 32-bit version of Windows. If you try to install a 64-bit version of Windows, it won't work; it won't even have the right boot loader file -- for a 64-bit UEFI, it's bootx64.efi, rather than bootia32.efi. OTOH, I'm only assuming that the tablet has a 32-bit UEFI; if I'm wrong, you'd need a 64-bit Windows, and you'd launch its boot loader using the bootx64.efi binary.

Comments

[Bryan Raynolds]

I checked other tablets and all of them are 32 bit windows on 64 bit processors. I created with rufus 32bit bootable disk but still after tablet reboots it cannot detect bootable usb. In EFI shell i only see fs0 and no fs1. By the way i can only connect one: usb flash or keyboard at time because if i connect both of them to usb extender then nothing works.

[telcoM]

In the EFI shell, once you have plugged in the USB stick, you can try running map -r to re-detect the disks. If fs1: appears then, you can proceed.