For those who are nervous about changing the registry, the same thing can be accomplished using an XP
dialog. (Obscure, but it's there)
1) On the search dialog click "Change Preferences"
2) Click "with indexing service" (this doesn't enable indexing - on the next screen you can enable indexing if
you want but it is not necessary to enable text searching)
3) Click "Change indexing service settings"
4) Click "Action" on the menu bar
5) On the "General" tab, check "index files with unknown extensions"
Click OK