Can a PC boot without a hard drive?

What should I put on the CD? Is there something specific depending on the computer used?

Hello
What should I put on the CD?
A free downloading Linux ISO for example.
You can take a small Toutoulinux in French which has plenty of options, booting from the CD or USB stick, capable of running entirely in memory freeing up the CD drive, several installation options from the OS in memory, etc.
http://www.moulinier.net/

ok Jumo,
thank you, I will try that as soon as I'm back. However, I hope I have time to boot up before the computer turns off.

Well, it shuts down too quickly to do anything... :(

Do you have any other ideas, brilliant internet users?

Did you change the battery? You need exactly the same model (normally, they are watch batteries)

Without a battery => no BIOS
No BIOS => no Windows
No Windows => well, you got it...

ok, little mechanic, backtrack seems interesting to use for a security audit. However, there's a slight problem: my computer shuts down pretty quickly - in 15 to 30 seconds from cold. So I won’t have time to boot into anything.

Clean it, it's definitely an overheating issue!

Otherwise, turn it on and leave it in the BIOS to see if it still shuts down.

How old is it?

I cleaned it, even though it wasn't very dirty.
No time to take it to the Bios, it shuts down before.
I bought it by mail order almost 2 years ago.

second-hand?
check the thermal paste

A computer can start up if it has a power supply, a processor, memory sticks, and a monitor.
Logically, it automatically starts the BIOS (not inside the BIOS) and scans your installed hardware.
Then it will tell you that there is no operating system installed (which makes sense if there is no hard drive).
After that, you can use an operating system pre-installed on a DVD or USB flash drive.

If your computer does not turn on, when testing, try the memory sticks one by one and check that your processor is properly secured. Usually, the speakers in PCs, if connected, emit repeated beeps indicating that something is wrong with the installation. Generally, it’s the memory sticks.

In short, good luck.

It's to test the equipment, I connected the hard drive to another PC to be able to scan it (indeed, my computer was shutting down, I thought it was a virus. But Antivir detected nothing, and neither did Malwarebytes). Before reconnecting the hard drive, I wanted to see if I could check from the hardware side.