Hp omen 17 blue screen stop code: critical process died

[anisali24]

Hi All,

I have a HP omen 17 an008ca laptop, came as a gift initially I was using this laptop on battery but it was frustrating every time to keep a check on if the battery has charged fully or not my main purpose was gaming so I decided to remove the battery and use this on direct supply for long hours right after removing the battery I started to see a checksum CMOS message which automatically disappears by an auto restart or if I press enter to restart and then everything works pretty well so I kept using this laptop like this for almost a year until suddenly 2days ago I saw a blue screen saying your device ran into a problem and needs to restart also there was a QR code below and a stop code critical process died after a restart I get into bios to see if there something wrong but bios looked perfect after another restart its showed me the same blue screen and got restarted again and showed me a screen saying diagnosing your pc and then another screen saying automatic repair with 2 option button restart and advance option so I clicked on restart but nothing happened showed the same screen 2nd time so I had to click advance option button this time which took me to another screen with several options, I am not specific but I think I saw these below options below
(startup repair)
(use a device)
(turn off pc),
(system restore),
(system image recovery),
(UEFI firmware something)
(uninstall updates)
for me system restore to a previous restore point seem ok to proceed with so I clicked and saw recent restore points but when I tried it nothing happened showed me some unavailable drive error C: with an exclamation mark tried this option again after restarting nothing happened than I finally decided to reset my pc with keep the files option or without neither of them worked and then I realized that there is some problem with the UEFI boot mode which is not detecting my HDD or SSD because in the bios when I entered on UEFI boot it showed a message no boot device found so than I swap UEFI mode with legacy mode and restarted it nothing happened because the drive partition were made on GPT style so they were unable to boot on legacy mode I guess than I decided to reinstall windows 10 created a bootable usb recall it from legacy mode got into windows installation screen but it didn’t allow me to overwrite the windows or install it on another drive showed a message about the GPT partition style so I used diskpart command cleaned the partitions and converted it into MBR and restarted it got into installation screen again and this time I was able to install windows 10 now the only concern I am facing is whenever I shutdown and remove the power cord and put it again the laptop shows me a screen saying  
“Boot device not found
Please install an operating system on your hard disk
Hard Disk <3F0>
F2 System diagnostics”  This is only happening whenever I am cutting the power completely not on restarts or shutdowns with power on so I checked on the bios again and saw the boot mode switched back to UEFI which was causing 3F0 so I changed it back to legacy and it booted fine  having said all this I was also doing some researches about this whole scenario also tried some commands like bootrec, sfc, chkdsk, rebuild, etc but no luck I just want to know if there is a easiest way to repair UEFI boot mode because everytime I shut down completely I have to do this whole thing of changing boot mode back into legacy sorry for my bad english,TIA