1. I've done a full system reformat, I think the PC is just showing its age. I don't know about the BIOS though.
I'm pretty sure it's a beep code error, hardware. Probably this one
"Continuous Beeps - Memory or Video Failure
Troubleshoot memory, graphics card, motherboard."
It always starts up after hitting on/off a couple of times. It doesn't always give a beep code error.
I'm thinking about checking the BIOS settings, not to fix this problem but because full system reformat wouldn't have reverted them to default afaik.
2. Afterwards. I restarted the PC since posting, which is the second time I'm talking about.
3. I don't remember which is why I wrote "something", it was around today and I remember selecting "shutdown" and was surprised when my PC restarted automatically.
4. I don't know. Power & Sleep says screen 10 minutes, sleep 30 minutes.
5. Every 1 hour