please search before posting:
http://www.zotero.org/search/#forums/highlight%20pdfs
short version: you can use an external tool such as acrobat professional, Foxit, or pdfXchange to annotate pdfs that are stored in Zotero. Zotero doesn't - and most likely won't - provide it's own pdf viewer.
Upgrade Storage
http://www.zotero.org/search/#forums/highlight%20pdfs
short version: you can use an external tool such as acrobat professional, Foxit, or pdfXchange to annotate pdfs that are stored in Zotero. Zotero doesn't - and most likely won't - provide it's own pdf viewer.