Why does my computer takes a long time to go off?

why does my computer takes a long time to go off after its been swtched off

If it's an old computer, there's not much to be done. If it's a newer computer & it's taking a long time to switch off, you might try removing some of the applications that are starting by default along with the booting up - things like instant messaging applications, firewalls, etc, add to both the boot up & power down time as the OS needs to shut each one down before turning off.