what is a .ffa file?

I didn't know either so I checked six sites and this is all I came up with:

EXT Search Results

You searched for file extension: .ffa

PR: Microsoft FastFind

Not very informative, I'm afraid.

It's from MS-Office, when you install it, it places a FindFast shortcut in your startup group. This utility scans all drives and finds all MS-Office files and keeps track of them. MS-Office uses this information to make retrival faster. So they claim.

You don't need Find Fast running to use any Office program. Remove it from the startup group and delete any *.ffa files you find.

TM

Microsoft Office's default setup includes a "Find Fast" utility that indexes your files supposedly to make opening an office document faster.

The .ffa, .ffo, .ffl, and .ffx files are part of that index. Article Q166302 in the Microsoft KnowledgeBase has more info.