That is not the proper definition of zero-day. Exploits are called "zero-day" by the "bad guys" for as long as the "good guys" are unaware of the vulnerability. The number counts up in age, not down from how long they should have been fixing it in the past.
Does the keyboard work during boot up / BIOS / etc, before windows/whatever loads?
ie, can you get in bios/system settings or boot to the dell diagnostics partition?