So close yet so far 
let me see if I can revert back to an older bios version
Couldn’t revert back to the old BIOS. I found this topic [TOOL] Lenovo (H20) Bios Unlocker and Locker. Don’t know if this could work out. —> NO.
Other than that I guess I’m out of options.
Since I’m still learning any feedback is always welcome!
Another update. After hours of searching the forums I came to the conclusion that I indeed only have the option left to use an SPI programmer as @Sweet_Kitten suggested.
With only four days of knowledge I find the risk of bricking using an SPI programmer too high. The amount of people bricked their BIOS (chip) with several warnings included is most likely due to lack of knowledge.
Overclocking memory speeds and tweaking some other settings is for me not worth the risk (at this moment) and I encourage everyone to think twice before taking next steps.
So that means I firstly will take more time to learn about modding. That said, I especially would like to thank @Sweet_Kitten for the effort!
Hello KewellH. Did a search for Legion T7 XMP BIOS unlock and found this forum and thread.
Like you, I’m trying to figure out a way to unlock the advanced BIOS for T7-34IMZ5. It seems you got stumped at trying to revert back to old BIOS? I have previous versions of BIOS dating back to last June 2021 and have messed around with reverting back to different BIOS versions. In order to revert back to previous BIOS versions, you have to go into the BIOS and disable "Secure Roll Back Prevention" and set it to "NO". Hope this helps in some way.
Oh, this is too bad. It looks like Lenovo added a system to prevent unauthorized changing of variables. There is nothing to be done about this without hardware BIOS flashing tools. Since disabling the protection mechanism involves modifying BIOS, it creates a circle. Last time I’ve seen this on HP device and only on it, but the tendency is expanding.
Sweet Kitten, thanks for help and work you have done thus far.
Can the BIOS/UEFI "Secure Boot" setting be the variable or culprit?
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What is Secure Boot?
Secure Boot is one feature of the latest Unified Extensible Firmware Interface (UEFI) 2.3.1 specification (Errata C). The feature defines an entirely new interface between operating system and firmware/BIOS.
When enabled and fully configured, Secure Boot helps a computer resist attacks and infection from malware. Secure Boot detects tampering with boot loaders, key operating system files, and unauthorized option ROMs by validating their digital signatures. Detections are blocked from running before they can attack or infect the system.
How does Secure Boot work?
Secure Boot works like a security gate. Code with valid credentials gets through the gate and executes. However, Secure Boot blocks at the gate and rejects a code that has bad credentials, or no credential.
Hi,
Can you maybe extract they key combo used to acces that part of the bios?Or do they use a dongle of somekind? There is a way to boot a bios from usb, but that was very limited ( see my post on biosmod). I’m still leaning these things, sorry if make no sense 
gr
Hi @KewellH , would you be so kind yo upload a BIOS dump for your T7-34IMZ5 again, please. It seems that this file is deleted. Thank you very much!!!