Are you talking about getting rid of it globally? If so, just hide it through Site Administration>Plugins>Blocks>Manage Blocks and click on the eyeball.
If it's a specific instance of the block, you can hide it by clicking on the gear/cog in the block header and selecting 'hide this block' from the drop down list.
I suspect it may be the 'Latest Badges' block on the Dashboard page that's giving you the problem though - in which case you need to edit it via Site Administration>Appearance>Default Dashboard Page and delete the block there (not sure what version you're on, but it's Dashboard in v2.9 but My Home in v2.8 and previous).
The Dashboard page is a little bit 'sticky' sometimes in showing the default page after it's been changed by an admin. It can be reset to default settings by each user - https://docs.moodle.org/29/en/Dashboard#Resetting_Dashboard_to_default. If you have access to your Moodle database, you can force reset to the default page using the instructions at https://moodle.org/mod/forum/discuss.php?d=169840#p1004708 - with the usual caveat of using it at your own risk!