I'm getting recurring BSOD events every day or two.  The system is an Inspiron 7777 and to be honest has been a nightmare right from the beginning.  I've tried all of the usal scans and tests but no issues are being found.  I've checked all of my dump file settings and even though everything seems to be set correclty, dump file creation is failiing as recorded in the event viewer.  

Prior to BSOD the system freezes.  For a few moments the cursor will continue to move and I can click on things but it's unresponsive.  Moments later it will blue screen.  If I then leave it to it's own devices to reboot, I get a PXE boot failure message.  However, if I click F2 and enter BIOS I can then exit the BIOS immediately and it will reboot without issue. At times when I've entered the BIOS, it seems the Boot Priorities have re-ordered themselves.  When I re-order with 'Windows Boot Manager' as the first priority, again the system reboots without issue.

BSOD stop codes are usually SYSTEM_SERVICE_EXCEPTION, UNEXPECTED_STORE_EXCEPTION, and more recently a CRITICAL_PROCESS_DIED.  

Reliability History shows regular APPCRASH relating to 'Host Process for Windows Tasks'  /  Application Name: taskhostw.exe  /  Fault Module Name: unbcl.dll.  And Event Viewer shows quite a few errors.

If anyone can help, it would be greatly appreciated.  I'm running out of patience and very seriously considering returning this PC.