Troubleshooting E2B

Use  this guide if you have trouble when legacy booting to E2B from a REAL SYSTEM.

If you are having problems with the agFM or Ventoy for Easy2Boot menu systems, check the relevant pages on this site.

If you are having a problem with a particular payload\ISO – check the Tested Payloads page.

Before starting any tests:

  • Download the LATEST VERSION OF E2B to a new folder and run the UPDATE_E2B_DRIVE.cmd script to update your E2B drive. If you did not make the E2B USB drive using the Make_E2B_USB_Drive.cmd batch file, make a fresh USB drive using it. Always use the E2B version of the \grldr grub4dos boot file – other versions may have bugs including more recent versions.
  • Check the E2B Version History for a new Beta version + bug fixes.
  • Ensure the MBR partition table contains two primary partitions (RMPrepUSB – Drive Info – 0)
  • Delete or rename the \_ISO\MyE2B.cfg file, if it exists – some user settings in MyE2B.cfg may adversely affect E2B or may hide informational messages.
  • Grub4dos allows for a limited number of environment variables (approx 60). You cannot specify too many ‘set’ commands in your MyE2B.cfg file or you may get strange grub4dos errors. If your MyE2B.cfg file seems to be causing issues and uses a lot of environment variables, you must reduce the amount of set commands that you use.
    Tip: do a fresh boot to the Main Menu and exit to the command line and type varsleft in the grub4dos command console – E2B should report at least 18 free variables at this point (typically around 40 free).
  • If there is a STRINGS.txt or MENU.LST file in the \_ISO folder, then delete it.
  • If you are having a problem with one particular payload file – delete the .txt file for it, if you have made one.
  • Make sure your BIOS is configured to MBR-boot (BIOS has CSM enabled).

Note: In some circumstances, the Windows Format utility can format a USB drive as a floppy disk (with no partition table or MBR) which will not boot correctly. Always use RMPrepUSB or the E2B script or Make_E2B.exe to make your E2B USB Flash drive. If you have just bought a new USB flash drive, test your USB Flash drive using FakeFlashTest (destructive test). 

Tip: If you have trouble booting grub4dos, try pressing the S key just as it loads grub4dos – you should see a 5 seconds countdown and it will use ‘safe mode’. Disk accesses will be much slower however. This is also a useful way of slowing down the grub4dos boot process so you can see any E2B or grub4dos error messages.  

Step 1 – Check MBR-booting using QEMU

Test booting to the Main Menu using QEMU

For a ‘boot to menu’ test, run the \QEMU_MENU_TEST (run as admin).cmd file as Administrator on the E2B USB drive. No matter what Windows system you have, a freshly-made Easy2Boot USB drive should ALWAYS boot to the E2B Main Menu when using QEMU.
QEMU_MENU_TEST runs a 32-bit CPU emulator – i.e. it emulates a PC system which contains a 32-bit CPU and a standard 32-bit non-UEFI BIOS (and no internal hard disk).

You can also test E2B booting use the version of QEMU that is contained in RMPrepUSB. Just run RMPrepUSB.exe, select the E2B USB drive that you want to test and hit the F11 key. If you are asked to set a Virtual Hard Disk size, you can either set 0 for no drive (just for testing that we can get to the Main Menu) or set the size of the Virtual Hard disk (e.g. 15000MB). For the amount of memory to assign to the Virtual Machine, you can use between 80MB and 900MB (it may not be able to run QEMU if you allocate >900MB of memory). Because QEMU uses it’s own BIOS and emulates the hardware in a Virtual system, it should always successfully boot to the Main Menu of E2B. If not, then something is wrong with the USB drive or it’s contents. On a real system – if it looks like it is booting from the USB drive, but you cannot see the E2B menu, it may be a graphics adaptor issue (it may not support the graphics mode used by E2B). In this case, copy the \_ISO\docs\Templates\TextMinimal\MyE2B.cfg file to \_ISO so that a non-graphics mode is used. 
Note: QEMU emulates a 32-bit CPU – you cannot boot 64-bit ISO files or 64-bit payload files from the E2B menus. If the problem begins once a 64-bit payload starts to boot, then test using VirtualBox and DavidB’s VMUB utility instead of QEMU. If you find QEMU is too slow, use Virtual Box + VMUB. This allows you to boot 32-bit and 64-bit payloads, can allocate far more memory and also can 32-bit and 64-bit UEFI-boot too. 

E2B not detecting some payload files?

Use the UTILITIES – ls menu to list the files in any folder on the E2B USB drive. Check that the filename and file extension is correct (spaces in grub4dos filenames will be preceded by a character). Make sure that the payload file does not also have a matching .txt file in the same folder. If it does (if you created one) then delete it and re-test. 

  1. Rename the \_ISO\MyE2B.cfg file to a different name so E2B does not use it.
  2. Use NotePad and create a file called NEW.txt – edit it and add some characters so it is not 0 size, save it and rename it as DUMMY.ISO.
  3. Make sure the file extension is .ISO and not .ISO.txt (configure Explorer to show file extensions).
  4. Copy the DUMMY.ISO file to various different E2B folders – e.g. \_ISO\MAINMENU, \_ISO\LINUX, \_ISO\WINDOWS\WIN8.
  5. Boot using QEMU, you should see the MAINMENU files being detected and the WINDOWS .iso and .imgPTN files counted (if any) – press SPACEBAR to pause the screen and check it. Press SPACEBAR twice quickly to continue to the next point.
  6. Press ENTER to continue to the Main Menu. You should see E2B report that at least one Windows Install file is present if you previously copied an iso into one of the \_ISO\WINDOWS\xxxx folders.
  7. Go to the UTILITIES Menu and choose ‘ls (DIR)‘ and then choose one of the menu folders.
  8. Check the name, extension and size of any payload file that was missing from the menu.

Step 2 – Test on several different REAL SYSTEMS (if you can’t boot to E2B)

If you are having problems booting to the E2B Main Menu on a REAL SYSTEM but it is OK on QEMU, then there must be a compatibility problem between the real system and the USB drive+contents. 

You cannot UEFI-boot to the E2B menu (MBR\Legacy boot only)

Tip: If you suspect a problem with your BIOS (e.g. boots with flashing cursor), always SWITCH OFF YOUR SYSTEM and then switch it on again to test a USB drive. Do NOT reset or reboot the computer (warm reboot) because the BIOS may detect the USB geometry and device type only on power up.
Always switch off between tests
For instance, on power-up, your BIOS may determine that your USB drive should be treated as a USB ZIP drive or USB Floppy drive. If you then re-partition and reformat the USB drive as a USB HDD, the BIOS may still attempt to boot it as a USB floppy unless you switch off and then switch it on again so that POST re-detects and re-enumerates the USB drive on power-up.To boot from an E2B USB drive, you must set up the BIOS\UEFI firmware correctly for MBR\CSM booting. See here for BIOS settings for different systems.  

Wherever possible, do not change the BIOS boot order (do not specify the USB drive as the first boot device) – instead, use a Function Key (e.g. F8, F9, F11, F12 or ESC) to bring up a BIOS Boot Selection (BBS) menu so that you can choose which device to boot from. This is because on some BIOSes, if you set the USB as HDD0, then some OS’s, once they have booted, may see the E2B USB drive as the first hard disk (boot disk) and may install boot code onto the USB drive instead of the internal hard disk! 

Note that some NoteBook BIOS menus have a BIOS setting which, if enabled, means you have to press Fn+F9 instead of just F9 (the actual Fn key may vary depending on the model) – i.e. you need to hold down the Fn key first. So if the manual says to press F9 and that does not seem to bring up the BIOS boot menu, try Fn+F9. Also, some BIOSes have a very rapid start-up and you need to switch it on quickly and then repeatedly hammer the correct key before it boots to Windows or Linux from the hard disk! Sometimes just holding down the key just after switch-on works too. Another strategy is to wait for a lit LED (e.g. keyboard or web cam or Num Lock LED) after power-on and then start hammering the BBS F8, F9 or F12 or whatever key required for the boot menu. 

BIOS Settings

Typical Legacy-boot BIOS settings required are:

  • Legacy or CSM = Enabled
  • Fast Boot = Disabled
  • USB Legacy = Enabled
  • Secure Boot = Disabled
  • Boot – Boot Priority – Legacy First

The first thing to do is try the same E2B USB drive on different types of systems (PCs, Notebooks, Tablets, QEMU emulator, etc.) – if some will boot to the Main Menu but others will not, then we know that there is a compatibility problem with certain types of systems. This type of problem can often be fixed by changing the BIOS settings (see below), re-making the USB drive using the Windows script provided or updating the BIOS version. If E2B partially boots, take note of any error or warning messages and look them up by using this site’s Search box. 

Note that some BIOSes will try to boot a USB drive as a floppy disk (which usually won’t work). If there is a second PRIMARY partition on the USB drive, most BIOSes will then treat the USB drive as a hard disk (which should always work). If using Linux, use gparted or fdisk to create a 2nd Primary partition (you may need to reduce the size of the 1st partition slightly). Do not use the last few MB’s of the drive in any partition – keep it as unused space – this is because done to avoid some grub4dos and BIOS compatibility issues when accessing sectors near the very end of the drive. If you use RMPrepUSB or RMPartUSB, this is all taken care of for you. Also, some bad BIOSes will directly boot to the boot code in the PBR, so ensure that grub4dos is installed to both the MBR and PBR. If you use the Windows E2B script/executable to prepare the E2B drive, it will automatically create two partitions and install grub4os to the MBR and PBR using RMPartUSB.  

Step 3 – Try a different USB drive and on different USB ports

Sometimes, some types of USB drive are not compatible with some systems/BIOSes. So install E2B to a different make/model/type of USB drive and try that on the real systems (or try a different system). Don’t worry if the USB drive is not the one you want to end up using – this is just a test. Try all USB ports on the system (USB 2 and USB 3 – switch off each time).

Problems have been seen with Mushkin USB drives, HP InSyde BIOS+Danelec/MSI USB flash drives, Emtec 64GB USB 3.0 color mix flash drives.

Beware of any USB drives that are very slow in use or cause your system to take a long time before the BIOS Boot selection menu appears. Test using RMPrepUSB Speed Test and Quick Size Test.

Do not use cheap, unbranded or slow USB drives. A Quick Size test should take a few minutes (not 1 hour+!) and the Speed Test should return at least 5MB/s+ speeds for both read and write. 

If you find that some USB drives work and some don’t, you should check that the BIOS is the most recent available for that system (see below). 

If you suspect that there is something about the USB drive that one particular system does not like, use RMPrepUSB to format the USB drive as FAT32+’Boot as HDD’ and then install grub4dos to the MBR and PBR. Then see if it boots to the grub4dos console. If it boots, try adding the E2B files to the USB drive. You can view the MBR and PBR using RMPrepUSB – Drive Info – 0 and RMPrepUSB – Drive Info – P1

Tip: Some USB Flash drives have badly-designed connectors and these may not make contact properly in some USB sockets which have weak springs. If you find it does not work in some USB ports but does in others, try using a short USB extension cable instead of plugging it directly into the USB socket. 

Step 4 – System Setup Menu (BIOS Settings)

There are two types of x86 systems – ones with the old IBM-compatible BIOS (so called MBR BIOS) and ones with the new UEFI firmware. Any retail system that contained Windows 8/10 when it was purchased, should contain UEFI-firmware.  You will need to enable CSM\Legacy mode in the BIOS before you can Legacy-boot to the E2B menu system.

MBR BIOS systems

Consult the manual for your system. Often you will need to enable USB booting, disable any Quick/Fast boot option and enable the USB ports in the BIOS Setup menu.  

Tip: To get to the BIOS Setup menu, you usually need to press a key (like DEL, ESC, F1 or F2).  If the BIOS supports a BBS menu option (BIOS Boot Selection menu) then it is best NOT to change the BIOS boot order, but press the BBS key (e.g. F8, F12, F10, ESC) to get a list of devices which you can boot to.

  • Disable Secure Boot (if UEFI system)
  • Enable USB 2.0 or 3.0
  • Ensure the USB drive appears in the boot list (as a hard disk, not as a Floppy or ZIP drive)
  • Enable Legacy/CSM/MBR/BIOS mode if a UEFI system
  • Disable Fast Boot
  • Make sure that no \EFI folder is present on the E2B USB drive (this sometimes prevents MBR booting to the grub4dos E2B Menu) if a UEFI system.
  • Some UEFI systems will not show the non-UEFI CSM boot option if a .efi boot file is present on the USB drive partition.
  • Ensure there are two primary partitions in the partition table on the USB drive
  • If it starts to boot to E2B but then hangs\crashes, try a USB 2.0 port or attach a USB 2.0 extension cable to force it to use USB 2. speeds.

Note: Some systems (e.g. Acer AO725) will not allow you to even see the Secure Boot or Legacy/MBR BIOS options in the Setup Menu unless you set a Supervisor Password first. Choose a simple password that you will never forget (or write it on the underside of the PC/laptop) 

UEFI systems

These systems may be set up to boot only from UEFI boot files only, or Secure Boot may be enabled.To boot from an E2B USB drive, you must disable Secure Boot in the UEFI Setup menu. Also you must enable Legacy Mode (often called CSM or BIOS mode).If the UEFI system supports a BBS menu option (BIOS Boot Selection menu) then it is best NOT to change the disk boot order, but press the BBS key (e.g. F10) to get a list of devices which you can boot to. On a UEFI system, you may see two menu entries for the same USB drive, one is for UEFI-booting from the USB drive (we cannot boot to the E2B Menu using UEFI) and the other will be for BIOS\MBR-booting (which is the one we need!)

BBS menu showing UEFI and non-UEFI boot options for the WD USB drive If you only see a UEFI menu option for booting from the E2B USB drive, then ensure that CSM\Legacy mode has been enabled and that the E2B USB drive does not contain a \EFI folder (there is no \EFI folder in the E2B download, so there should not be one on the E2B USB drive!). This is because some UEFI systems will not offer a non-UEFI CSM boot option if a .efi boot file is present on the FAT32 USB drive partition. For more UEFI info and if you have any trouble booting UEFI payloads – see the Useful things to know page. 

Step 6 – Update the BIOS\Firmware

Sometimes the system’s BIOS\UEFI firmware contains bugs. Check the manufacturers website for a later version and update your system. 

Step 7 – Disconnect all other USB devices

If you have other USB devices (e.g. card readers, other USB drives, USB wireless mouse dongle, USB printers, etc.), disconnect them before you switch on the system and try to boot from the E2B USB drive. Also try different USB ports (rear and front, USB 3.0 and USB 2.0). Do not use a USB extension cable, connect the USB drive directly to the USB port.If you find you can now boot, re-connect each device again until you find the one that is causing the problem – then try connecting that one to a different USB port. If grub4dos is not loading correctly or hanging, there may be an incompatibility somewhere else. If possible, temporarily disconnect or disable the internal hard drives and CD\DVD drives. If possible, change the graphics card. 

Step 8 – Contact Me

Use the Contact Me form to contact me and ask for advice. Please let me know what happened when you tried each of the steps above together with any successful combinations and any failing combination. e.g. test case scenario:

  • Case 1: HP Pavillion + Mushkin 16GB USB 3.0 flash drive – works in QEMU but not when booting from other real system
  • Case 2: HP Pavillion + Corsair Voyager GT 32GB USB 3.0 flash drive – works in QEMU and when booting from other real system
  • Case 3: Dell + Mushkin 16GB USB 3.0 flash drive – works in QEMU and also when booting from real system but not the specific DELL model.

This clearly shows a problem with the HP BIOS and Mushkin USB drives (this is just an example).

PC/Notebook will not boot at all?

Some BIOSes have a strange bug where sometimes they will not boot from any drive and may seem to get stuck during initial POST (e.g. Asus Z87). This is usually fixed by disconnecting all USB drives (usually only disconnecting the E2B drive is sufficient) and then switching on the system. Once it has booted successfully, you can replace the USB drive(s) and reboot either to the USB drive or the internal hard disk again. On my Asus Z87 this happens about once or twice a month and I have never been able to identify the cause!

Another common problem is that you have booted to a (usually Linux) ISO from the USB drive, but then you find you can no longer boot to your internal hard disk again. This seems to occur quite commonly on some notebooks. The reason is that Linux has programmed some of the internal chipset registers to a state which prevents your BIOS from booting. The solution is to switch it off, remove all power (including that large Li-ion battery if using a notebook), press the power button (with no power connected) to discharge the main board, wait 30 seconds or so and then reconnect the power (and battery) and switch it on as normal. This ensures that the chipset registers are reset to their default power-on state. Typically, you will find that every time you boot to that same Linux ISO, the same reboot problem will happen. Sometimes a more recent BIOS update can fix the issue.

Very old PCs

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How to prepare a Easy2Boot USB drive using FlashBoot

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Easy-to-read eBooks are available in PDF format (each eBook is over 100 pages) – rated 4.5/5 stars.
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