For Webinar Free accounts, your presentation recording will be available to download for 30 days after you host your webinar. Attendees can watch the recording during that time if you chose to allow video replays. To avoid losing the recordings, you'll need to upgrade your account before the 30 days.
For Webinar Premium and Webinar Pro accounts, your presentations will be available to download until you delete them. If you chose to allow video replays, attendees will be able to view the presentation until the webinar is archived or you delete the recording.