Sorry if I missed something, but..

[MiMc]

I downloaded Project64 and Legend of Zelda: Ocarina of Time and Legend of Zelda: Majora's Mask. Now I have a problem, I installed them in the docs/rdb file, but now when I go to open them I can't find them. On the page it said I might have to change the file type, but I have NO idea how to do that... help?

[HatCat]

The RDB file already defines some recognized games; if you needed to enter new text yourself you wouldn't have a clean copy.

First check if in Project64 you can find the files and open them through File/Open or Ctrl+O, browsing to where you downloaded them.

[MiMc]

I downloaded them from here, the download page. I mean, you'd think they'd be pre-verified? I can find them, (After I change the extension) I just can't play them. I change the file extension and it says it can't play it, but if I don't change it, then it doesn't appear in the list.

[Topken]

appearently you didnt download the games them selves sence if you did they would be about 32mb's in size each

[HatCat]

So you should give some info about the file sizes.
If you can actually manage to describe where/how you downloaded them without giving names that'd be great, too.

Download accelerators can cut things off as well.

[Truth Unknown]

Be somewhat vague on where you downloaded it, its somewhat illegal to be downloading ROM data from anywhere other than the Cartridge itself. We can't have everyone going around making trouble with links or names of places they downloaded ROM data.

What would work would be to post what the File Type or Extension (not what you changed it too) of the Game and the Size of it.