Outlook (all versions) stores the master category list in the stores the master category list in the registry. This is absurd, but since only a tiny number of Outlook uber-geek users care about Categories (tags in modern parlance) it’s not a big deal.
For Outlook PIM-geeks, it means changing machines deletes the list. Individual tasks retain their categories (the string is stored in the PST), but there’s no corresponding Master Category List entry.
Here’s how I regenerate under these circumstances:
- Export all tasks to Access. (this is easiest for me, other formats will work better for non-Access people)
- Dump all categories into a text editor (I use TextPad)
- Turn them into a list (trivial grep task) and sort with duplicate delete.
- Edit and cleanup.
- Turn into comma-separated strings.
- Copy and paste into the Master Category List enter box
It only took a few minutes to regenerate my MCL this way.