I’m normally not a cynical person on these boards, but…
After Effects CS3 was released in July 2007. So you’re telling me that you lost installers for valuable 3rd party plug-ins that you’re presumably paid for within 28 months? I don’t know about you, but I treat installers like these like gold. They’re always accessible on my system and backed up as well.
…
That being said, look in AE CS3/plugins. If you’re on a Mac, also look in /Library/Application Support/Adobe/Common/Plug-ins/CS3/MediaCore/ Don’t know what to tell you for Windows.
Adobe CS3, Apple FCS2
[Disclaimer: Sometimes I am an idiot and misinterpret people’s posts. I’m sorry.]