Last year, I purchased a minecraft account on my pc, but I need to change my pc, so can we download minecraft launcher and connect it to our account or I need to buy something.
If we can do it for free,can someone tell me how?
just goto minecraft.net, login with your account and download/play, your old account should still work as it did before, its not locked to your old computer
Just log in at https://www.minecraft.net
and then click download.
Or you can download it without being logged in, though it's a bit harder to find, and then log in in the launcher.
Until you're logged in in the launcher you can only play the demo mode and have to reset every 5 minutes.