So you finally got fastboot to recognize your device? That's worth celebrating!Thank you both for your precious help and patience with this rookie.
The entry in device manager is now "ADB interface". Before was "android".
I installed the latest platform-tools, thank you so much! Regarding the usb drivers, I think I have the latest because Lenovo page didn't offered alternatives.
This time I've tried PowerShell not as administrator.
I saw this topic https://forum.xda-developers.com/t/no-fastboot-devices-but-can-use-adb-devices.3485186/post-69252588 and followed those instructions. I didn't found the " Android Fastboot Interface " drivers but I choose "adb interface".
Now "fastboot devices" command is working!
View attachment 5220847
I still didn't tried to unlock the bootloader. I, as rookie, have to read very carefully the first post so I don't brick my tablet.
But I have a question: When I unlock the bootloader, the tablet will continue to receive the OTA updates?
I'm asking because the android 10 update is full of bugs. The most recorrent is outlook constantly crashes. I uninstalled outlook because don't use it, but the google file manager app keeps going to the previous update version every time I shut down the tablet. And if I don't update the app I can't read the sdcard. Uninstalled too.
Lots of people in Lenovo forum are complaining and downgrading to android 9.
Everyone is hopping that Lenovo comes with a new update to rectify all those bugs.
You can take the OTA update with the bootloader unlocked - I was able to get the OTA update from 9 to 10 when it came out. You can't take the OTA if you're rooted with the Magisk patched boot image, but it's enough to just flash back the original boot image. You can then do the OTA, then patch the new boot image with Magisk and reflash it and you'll have root again.