Notebook Operating System and Recovery

Hi,

I bought my HP Envy 360 in November.  It came with Windows 11 pre-installed.  I have noticed that it randomly crashes or reboots when it is running on battery power.  This does not happen when I have the charging cable connected.

I have received the blue screen of death and the a variety of error codes.  Unfortunately it flashes up so quickly, I haven't managed to catch all of them.  

The one that I did manage to quickly take a picture of was WHEA_UNCORRECTABLE_ERROR but I have had others.  A numerical code containing several 0's and ending in 21a (I think).  I had something about a CRITICAL_PROCESS too.  

Sometimes I don't get any error message, it just reboots.  It happens at random times, regardless of whether I'm using the computer or not.  The battery is fully charged and there is no sudden drop in the level.  There is no warning that this is going to happen.

I have tried repairing Windows by returning it to its default state and I have run the HP Hardware diagnostic tests.  I have run the chkdsk function and checked my drivers.  They are all up to date and I have no conflicts.

I saw somewhere that you can generate a log file to capture these errors and tried to do this but when I try to access the Memory Dump file, it tells me that I don't have permissions?  I have download the Windows utility to enable me to read the log but that reports the same thing.

Is there any way to capture these errors in a log so that I can at least try to pin down what is causing this?

I really don't want to have to purchase Windows 10 in order to use my laptop and it is important that I use it without it always being connected to the power.

Thanks for your time!