How can I force Windows 7 to REindex a folder?

Control panel->indexing->advanced->rebuild

I've seen several similar questions and as far as I know there's no way to reindex just one directory. Would be great if someone could prove me wrong though.

You can re-index a single directory:

Folder properties --> Advanced --> untick index --> apply changes

Go back to Advanced --> tick the index files option again

This will now re-index that particular directory. Hope this helps.

I've found no other working solution for re-indexing just one specific folder than that:

1. close all open programs, which may access the folder in question
2. copy your folder. For example if your folder is named to_be_indexed, copy it to a new folder named to_be_indexed - Copy. In Windows Exlplorer you may simply use ctrl-c ctrl-v shortcuts, having selected the folder to be re-indexed
3. wait for indexing to complete (check Windows "Indexing Options", status is given on top of window)
4. remove the original folder to_be_indexed. Be careful to check before if your copy in step 1 was successful - you do not want to lose data ... (if you want to play safe, rename to_be_indexed to to_be_indexed_old and delete it later)
5. rename to_be_indexed - Copy to to_be_indexed
6. wait for indexing to complete (check Windows "Indexing Options", status is given on top of window)
7. to_be_indexed is now re-indexed in Windows Search

Cumbersome, but works.