Thank you. Yes I'm not particularly worried about it. I've used old netbooks with warning triangles and not bothered to instal the drivers and never had any issues! I knew what they were - it was usually an sd card reader or similar. If it worked I used it. But it's good to have an understanding of what this IMEI is - seeing as it seems it's on every computer virtually.
So drivers. I tried the May 2018 above but decided not to use it - it seemed to install some other Intel software as well. When removing it, Windows reverts it back to the 2015 driver. I tried the 2024 driver mentioned above from DriverPack (although was very apprehensive downloading a driver from a driver site rather than HP) and it seemed ok. I also had a 2023 driver suggested by someone on the HP forum - which was from an Elitebook. Computer didn't seem keen on this one. It didn't have any install dialogue and left the blue circle going round a lot. So uninstalled that again.
It seems better on the 2015 one provided by Windows update, so I guess I'll either just leave that installed or try leaving the 2024 one in and see how it goes.
After a bit of googling I found the 2024 driver is directly from Intel. Although not available to download from Intel (which I'd rather do than use Driverpack) because they seem to have a more recent version now.
So it's either the correct (ancient) one for the machine from HP or an Intel latest one.
I wasn't keen on the file name of the 2024 one from Driverpack - which was Intel-FORCED-HECI-10x64-2441.7.0.0. ie why does it have FORCED in caps in the name?
So that was 2441.7.0.0 - googling that told me it was Intel's own driver.
The latest one from Intel seems to be 2451.7.6.0
Intel® Management Engine Drivers for Windows 10* and Windows 11*
www.intel.com