hi, when I install zotero and run it for the first time and click show file. firefox ask me to associate to an application. I did it wrong, how can I change it now?
Do you mean View File or Show File? It would also help if you would tell us the exact text in the open/save dialog.
View File either just opens the file in Firefox if Zotero detects that Firefox can handle the file natively or with a plugin or else launches it via the OS. You shouldn't ever see the Firefox open/save dialog, and if you do you might want to delete close Firefox and delete mimeTypes.rdf in your Firefox profile directory, which contains file type associations and can sometimes get corrupted, leading to File opening weirdness.
Show File varies depending on what OS you're on—you don't say—but it either "reveals" the directory (e.g., displays it in Finder on OS X or Explorer on Windows) or "launches" it via the OS.
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View File either just opens the file in Firefox if Zotero detects that Firefox can handle the file natively or with a plugin or else launches it via the OS. You shouldn't ever see the Firefox open/save dialog, and if you do you might want to delete close Firefox and delete mimeTypes.rdf in your Firefox profile directory, which contains file type associations and can sometimes get corrupted, leading to File opening weirdness.
Show File varies depending on what OS you're on—you don't say—but it either "reveals" the directory (e.g., displays it in Finder on OS X or Explorer on Windows) or "launches" it via the OS.