Lenovo 100s ideapad Bitlocker problem after Windows update Nov 2018.

hi supplyrabbit402

to resolve your issue get on to Lenovo get a factory reset usb stick there might be  a charge

you are correct that bitlocker is not in home product  and when i purchased mine calls to microsoft clearly stated it was not but when i got the updated and contacted them again it is inbuilt but you can activate it if you

want to but it is complected to do hence a 7 month enlargement with both lenovo and microsoft both blaming each other but when i found out with research that microsoft and certain manufacturers 

A to keep costs down  uefi was used instead of bios to basically stop people using other o/s Linux and so on

B so you could not boot from usb 

Whenever you need to boot from the USB drive in your computer (or change system settings), you always hear people say that you need to go to the BIOS to change the boot up settings. If you are a Mac user, you are probably wondering what BIOS is, since there is no BIOS to start with. Mac uses UEFI.

In this article, we will clarify the main differences between UEFI and BIOS and which one is better in any given circumstance.

The basics

BIOS and UEFI are two firmware interfaces for computers which work as an interpreter between the operating system and the computer firmware. Both of these interfaces are used at the startup of the computer to initialize the hardware components and start the operating system which is stored on the hard drive.

BIOS works by reading the first sector of the hard drive which has the next device’s address to initialize or code to execute. BIOS also selects the boot device that needs to be initialized for starting the operating system. Since BIOS has been in use since the very beginning, it still works in 16-bit mode, limiting the amount of code that can be read and executed from the firmware ROM.

UEFI does the same task a little differently. It stores all the information about initialization and startup in an .efi file instead of the firmware. This file is stored on the hard drive inside a special partition called EFI System Partition (ESP). The ESP partition will also contain the boot loader programs for the Operating System installed on the computer.

UEFI is meant to completely replace BIOS in the future and bring in many new features and enhancements that can’t be implemented through BIOS. Some of those features are discussed below.

Breaking out of size limitations

BIOS uses the Master Boot Record (MBR) to save information about the hard drive data while UEFI uses the GUID partition table (GPT). The major difference between the two is that MBR uses 32-bit entries in its table which limits the total physical partitons to only 4. Each partition can only be a maximum of 2TB in size, while GPT uses 64-bit entries in its table which dramatically extends the support for size possibilities of the hard drive. (More on difference between MBR and GPT).

Speed and performance

Since UEFI is platform independent, it may be able to enhance the boot time and speed of the computer. This is especially the case when you have large hard drives installed in your computer. This enhancement depends upon how UEFI is configured to run. UEFI can perform better while initializing the hardware devices. Normally this speed enhancement is a fraction of the total boot time, so you will not see a huge difference in overall boot time. Developers can make use of UEFI shell environment which can execute command from other UEFI apps optimizing the performance of the system further.

Security

Secure boot is a feature of UEFI that has been implemented in Windows 8 recently. The biggest benefit of UEFI is its security over BIOS. UEFI can allow only authentic drivers and services to load at boot time, making sure that no malware can be loaded at computer startup. Microsoft implemented this feature to counter piracy issues in Windows, while Mac has been using UEFI for quite some time now. Secure Boot works by requiring a digital signature of boot loaders which should require digital signature by the Kernel. This process continues until the operating system is completely started. This secure boot feature is also one of the reason why it is more difficult to install another operating system on a Windows machine.

hi supplyrabbit402

that did not go as i planned but you will see now what i mean 

regards beverleypage

Any NEW information from Microsoft or Lenovo on how to fix this problem without having to WIPE your hard drive?

This computer is way past its warranty period and not mine. Trying to fix it for a friend.  And, they actually weren't the original owner themselves it was a hand me down from the original owner to them.  So, getting a recovery USB Key from Lenovo is most likely a pay them to provide the fix for a problem that should not exist. 

There is a recovery partition on the internal 32GB eMMC (SSD or whatever) solid-state drive in this computer of 1000.0 MBs -  partition 4, not the one highlighted that's the BitLocker encrypted Windows OS partition - partition 3.

Nothing happens though when I boot the system with the Lenovo button and go into System Recovery to try and reinstate the original factory configuration. I guess the System recovery option doesn't know how to recover the system when the Primary Windows Partition is a BitLocker encrypted one. (The picture above was taken of the 100S after booting the computer starting it with the Lenovo button with an UEFI bootable USB thumbdrive with Windows 10 1903 on it.  It was created with the Windows 10 Media Creation Tool from Microsoft.

I could Delete the partition and reinstall Windows 10 but still waiting for a solution that doesn't involve losing data stored on the eMMC's primary partition 3.  However, I don't think that solution will ever come. :(

Other questions:

How did the update enable BitLocker to encrypt the drive?  

If BitLocker has in fact encrypted the drive, why was the computer user never asked to store the recovery key somewhere?

About the recovery partition...

Reading a bit more on these - no make that - Lenovo's forums. The recovery partition contains only the tools to run the system recovery.  It does not contain the actual recovery image itself.  You have to request that from Lenovo.  They should provide the recovery USB Key with the computer when you purchase it!  Without it, you can't recover the system. 

What good is a one-button Recovery system that you can't use without getting something else to do the actual recovery?