I would like to install Linux on an old laptop. what is the best Linux distribution for weak hardware on a mechanical HDD, I already use Linux mint on my main computer but I would like something more lightweight for an pentium based laptop
There are several lightweight Linux distributions that are ideal for running on older hardware with weak specifications. Here are some popular options:

1. Lubuntu: Lubuntu is a lightweight version of Ubuntu that uses the LXQt desktop environment. It's a good choice for older machines, as it requires very little processing power and RAM to run smoothly.

2. Puppy Linux: Puppy Linux is a minimalist Linux distribution that can run entirely in RAM, making it ideal for older machines with limited RAM. It also has a small installation size, which is ideal if you're installing it on an older mechanical hard drive.

3. Xubuntu: Xubuntu is a lightweight version of Ubuntu that uses the Xfce desktop environment. It's designed to be fast and efficient, and can run smoothly on older hardware.

4. Peppermint: Peppermint is a lightweight Linux distribution that uses the LXDE desktop environment. It's designed to be fast and easy to use, and can run smoothly on older hardware.

5. AntiX: AntiX is a fast and lightweight Linux distribution that's designed to be used on older machines. It uses the IceWM window manager, and has a minimal set of pre-installed applications to reduce resource usage.

These are just a few options to consider. It's important to choose a distribution that's compatible with your hardware and meets your needs in terms of functionality and user interface. I recommend trying out a few different distributions to see which one works best for you.