Hello,
I have a corrupt BIOS/UEFI and need to re-flash it. Lenvo only gives BIOS as .exe files, lovely people. The way this should work is:
Download their BIOSupdater.exe
Use innoextract to extract another .exe from the first exe
Use 7z to extract from the second .exe
I'm currently stuck at step 3. After using innoextract on the original BIOSupdaterProvidedByLenovo.exe, I get another .exe file (SecoundEXThatShouldExtractWith7z.exe). According to the guide, 7-Zip should be able to extract this second executable as an archive to get the actual BIOS image file (usually a .fd or .rom), but 7-Zip just reports that it's not a valid archive.
I'm not sure if this is:
A problem with my 7-Zip version (24.09)
A change in Lenovo's packaging that broke the old method
Something else entirely
Any guidance would be greatly appreciated—I'm dead in the water without a working BIOS
EDIT: The original Lenovo BIOS Updater .exe can be found here.
Last edit: CocolinoFan 2025-08-27
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With all due respect, why would you attach 28 MB to the post?
First file is publicly available so it only needed link to it, and second one, from innoextract, you could put in some temporary cloud service.
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Your file uses very complicated encodings.
There are many lzma streams and exe files inside.
lzma stream is not detected by default. So you must split the file manually excluding data before each new lzma stream. For example, you must type 32 1g in split's window for "volume size" field to skip first 32 bytes before lzma stream.
Sometimes parsing can help:
7zx-t#archive
Last edit: Igor Pavlov 2025-08-26
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Sort of. I did manage to get the cap file at one point, but that has to be further cut down to size. For this specific BIOS you need a dump of the old BIOS, cut some pieces from the blob and put them into the new BIOS. A total mess. [Best help I found] for firmware, and how I got mine, is to go to and see if you can find a thread about your specific BIOS.
Don't worry if is an old version, you can make a recovery USB with [Medicat], boot the windows they have there, download the latest update .exe from Lenovo; run the installer but extract, don't fully install; and then fully install what it was extracted.
Last edit: Igor Pavlov 2025-09-11
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
I have a corrupt BIOS/UEFI and need to re-flash it. Lenvo only gives BIOS as .exe files, lovely people.
The way this should work is:
I'm currently stuck at step 3. After using innoextract on the original
BIOSupdaterProvidedByLenovo.exe, I get another .exe file (SecoundEXThatShouldExtractWith7z.exe). According to the guide, 7-Zip should be able to extract this second executable as an archive to get the actual BIOS image file (usually a .fd or .rom), but 7-Zip just reports that it's not a valid archive.I'm not sure if this is:
A problem with my 7-Zip version (24.09)
A change in Lenovo's packaging that broke the old method
Something else entirely
Any guidance would be greatly appreciated—I'm dead in the water without a working BIOS
EDIT: The original Lenovo BIOS Updater .exe can be found here.
Last edit: CocolinoFan 2025-08-27
With all due respect, why would you attach 28 MB to the post?
First file is publicly available so it only needed link to it, and second one, from innoextract, you could put in some temporary cloud service.
Your file uses very complicated encodings.
There are many lzma streams and exe files inside.
lzma stream is not detected by default. So you must split the file manually excluding data before each new lzma stream. For example, you must type
32 1gin split's window for "volume size" field to skip first 32 bytes before lzma stream.Sometimes parsing can help:
Last edit: Igor Pavlov 2025-08-26
I am sorry for my bad posting etiquette 🙇 you're absolutely right. I was selfishly hoping for a quicker reply. I will delete the attachments.
Thank you Sir. Igor!
7z x -t# archiveworked!One step closer to getting that bios.
Thank you. Appreciate reflection and wit.
Just provide a link to original file so others can benefit from it.
Do you manage to get the bios? I'm getting stuck after extract the second executable.
Sort of. I did manage to get the cap file at one point, but that has to be further cut down to size. For this specific BIOS you need a dump of the old BIOS, cut some pieces from the blob and put them into the new BIOS. A total mess.
[Best help I found] for firmware, and how I got mine, is to go to and see if you can find a thread about your specific BIOS.
Don't worry if is an old version, you can make a recovery USB with [Medicat], boot the windows they have there, download the latest update .exe from Lenovo; run the installer but extract, don't fully install; and then fully install what it was extracted.
Last edit: Igor Pavlov 2025-09-11