At some point in the past years I was able to find notebook content via Windows Desktop Search (WDS). Recently I've had trouble with this (null results searching for content and "ext:nb"). I checked WDS Indexing Options, and found a problem with file extensions "cdf", "nb", "nbp": "Registered IFilter is not found". Extensions "m", "ma", and "wl" appear to not have such a problem, with WDS reporting "Plain Text Filter". I notice this after a clean install of both v11.3 and v12.
If the relevant IFilters are indeed installed on my system, perhaps my company's IT security policies are preventing their proper registration. I ran the installers as admin, but perhaps that wasn't enough.
I have just noticed I have the same problem. Windows 10 and Mathematica 12.
Spelunking on StackExchange suggests WDS capability was lost back around v10.2. It is a painful loss.
Can someone tell me how can I just use Plain Text IFilter with nb format? Since I am also getting Registered IFilter is not found. I am fine with just using a plain text filter but don't know how to associate the plain text filter with nb format.
I would contact Wolfram support to provide you with the Windows installer for the MathematicaExtras. This will enable Windows to index nb, m, etc ... files. It seems this relevant tool got "forgotten" in the recent Mathematica installers for Windows.
It's very annoying but I found a fix with up to now no side effects.
It seem that the .nb extension has no iFilter driver linked. I believe this could just be the standard .TXT.
Windows 10 and MM12.o
You can start regedt32 from the windows run prompt.
Go to the
Double click on the Default item and copy the GUID in my case as an example:
Go to the
Double click on the Default item and Paste the GUID from the .txt (In my case there was no GUID entry in the Default entry which I guess triggers the "not registered message"..?)
That's it and it worked for me. Would love to hear official Support statement from Wolfram though..
I also noted that for the .m and .ma files the same entries are used and these already worked as already explained by the OP.
Thank you, I'll try this. However, I expect it to be a little less efficient, as it'll search the entire notebook contents, which include images, compressed data, etc. I'd think an iFilter designed for notebooks would skip over such content.
Yes that is true. However this shortcut did help me
looking into the notebooks. A custom iFilter should make
things better. Going through the extension and their
filters it seems only the standard txt filter is used. No idea if Wolfram research is designing a custom filter.