Hi, I am a Legion Y540 user and I bricked my laptop downgrading from 41ww bios to 26ww, which was definitely Lenovo's fault.
But I bought a ch3341a programmer. After backing up the corrupted bios, I flashed the stock bios successfully, but it turned out many motherboard variables are missing.

Then I found a tool called LVAR by lenovo and wrote most of the variables back refering to my original box and labels on my laptop, including product name, mtm number, sn, etc..
But for other variables, it's really hard to know the original value.

Is it possible to extract UUID and my oem win10 license info from old backup?
Here's my corrupted bios backup. Thank you!

EDIT by Fernando: Thread title shortened

Never mind. I solved it.

Using UEFITool to open backup image file and found an padding area at the start of bios region, which is from 60000 to 6CCFFF. After comparing with official bios image, this padding area should be DMI info area.

So I replace with the padding area and flashed it into bios chip by ch341a, then I got my dmi info back, including uuid, win10 license, sn, etc...

Hope it would help if anyone else encountered the same problem.

Many thanks friend, It's that I were looking for also !!!

i have same problem withy lenovo thinkpad t8.
Do you think that sn, mac address etc is stored in same area?

try UEFI tool to compare every padding aera of an empty bios and your backup. You may find something.
Search UEFI tool by google as I can't post link here...