First I'd download SpeedFan and check the temperatures. If the cores are under 50 degrees C, you're OK, if over 65, you have an overheating problem, in between bears watching. If that's not it, I'd run the memory diagnostics. Windows 7 has them built in. You could also run chkdsk and let it check for and attempt repair of bad sectors.
HPE-400f Pavilion has been crashing to black screen with cursor with problems booting windows 7. Was getting BIOHD4 error code, then BIOHD3 -- Warning: No Active Partition. Installed 2 spare hard drives to alleviate crowding but problem continues. In troubleshooting have noticed the boot-up priority order keeps changing, so that the HDD group is not first, and also so the main - OS C: - hard drive is not on top of the list. Correcting these problems allows windows to boot up just fine, but then random crashes or bootup failures continue (constantly). Have taken everything out and reconnected, done a clean install from HP disks (reformatting and wiping the HD), system repair, virus scans, etc., yet problem continues. How can I fix the boot-up routines so the computer keeps them as they should be and doesn't keep rearranging them on its own thereby causing Windows to hang up? Thanks for your time and help.