The Finderbar is a little program for seeing Mac OS X style drop down menus added to the 7 task bar. It probably works much like any other small freebie going on fast and easy to remove if you decide to later. It's a customization option more or less there.
How well it works is something to be found out. As for an alternate download page, Finderbar 1.5 download free - Adds Mac OS X Style drop-down menus
Generally you shouldn't be seeing any 404 error unless you have a problem with your browser like needing to clear out the cache and offline content or the server got timed out too fast on that particular day. I've seen that often enough where you wait for a bit and go back and all is fine.