By default, Zotero stores files in a folder within the Firefox profile directory. It is possible to change this location. Zotero will not, however, copy over existing data to the new location. If you want to keep your data, you need to move the files manually. From then on, Zotero will store newly created data in the new location. Clicking the “Show Data Directory” button will open the Zotero directory in your default file browser. In most cases, you want to copy or move the entire contents of the 'zotero' directory—'zotero.sqlite', 'storage', and other files—to the new directory.
If you're using auto-syncing, you may want to disable it temporarily from the Sync pane of the Zotero preferences before changing the data directory. Otherwise, if you accidentally start Zotero with the wrong data directory set or before moving data, Zotero will attempt to pull down your entire library from the server.
Check Database Integrity - Checks for any data corruption in the Zotero database. Database corruption is rare, with most cases originating from older Zotero installations used with Firefox 2.
Reset Translators… - Reset the translators to the current Zotero defaults using the latest versions from the Zotero server.
Reset Styles… - Reset the styles to the current Zotero defaults using the latest versions from the Zotero server.
See Debug Output Logging.
Here you can specify a different OpenURL resolver for use with Zotero's Library Lookup feature.
If you are on an institution network, you can click the “Search for resolvers” button. If Zotero finds an OpenURL resolver belonging to your institution, you can select it using the “Custom…” drop-down menu.
You can also enter an OpenURL URL by hand in the Resolver field. Most resolvers use OpenURL version 1.0, but 0.1 is still in use. Ask your librarian for more information, or check our own list of OpenURL resolvers.