Welcome to the forums.
Knowing exact system specs would be a good thing.
Open the Terminal an copy and paste this command.
How to open terminal.
Linux Mint Cinnamon:
Menu - Administration - Terminal
Linux Mint MATE:
Menu - Terminal
Linux Mint Xfce:
Menu button - System - Xfce Terminal (Terminal Emulator)
Copy and Paste the output in a post.
Linux Mint any version has always booted slow from my experience although I use 8 year old and 10 year old junk computers with Core 2 Duo processors and 4.0 GB ddr2 ram.
Well by-golly that's one solution!Oh, I forgot about this forum. Thank you all for your help! I've found another solution: switching to Arch Linux, that boots up in a few secons.