DISCLAIMER: This is not intended to be a *complete* guide to cover all possible ways that one can botch an upgrade - rather, it is intended to cover one of the most frequent problems that people encounter when upgrading from one release of Slackware to another (or more recently, from the latest stable release to -current).
If you've failed to read UPGRADE.TXT / CHANGES_AND_HINTS.TXT before attempting an upgrade to Slackware -current, you possibly/probably wound up with errors about GLIBC stuff not found or "kernel too old" and such. This document should help you (mostly) return your system to its previous state so you can start over and do the upgrade correctly.
Enough chatter - here's the link:
http://rlworkman.net/howtos/glibc-recovery
