Slow start-up can indicate a number of things, first thing to check is what's starting with windows?

Task manager/Start-up tab and check the programmes that start automatically. Believe me most of them don't have to start until and if you need them. Specially look for items that have a "Start-up impact" noted as high. just click on the Status "Enabled" and you can disable them. you can't do any harm if it's needed you can always reverse it. I have a few on my comp I want to start up but I could safely disable the lot.

The other thing is that over time any system gathers a great deal of software crud and it's a good idea to refresh the system.
By refreshing you don't lose any of your programmes or data.
If in doubt don't do it.
CC cleaner is fairly safe if used judiciously.

Age of the laptop doesn't matter, with proviso, of course I'm not talking about steam driven ones but I run a 6 year old Acer quite successfully. Sure, not as fast as my new one but plenty fast for watching betting screens.