For some reason Shellbag Analyzer and Cleaner 1.25
just showed up on Snapfiles today. Perhaps they just got around to notifying Snapfiles of their new version(released March 5, 2016.)
Anyway, I know from issues on Windows Vista, Seven and Eight forums that Explorer shellbags can have old information and run out of room for new stuff. Which is why Explorer can forget folder size and window placement information. What this analyzer and cleaner does is sift through all the shellbags in the Registry and produce a report. Then you can erase the shellbags left over from deleted folders and/or optimize the remaining shellbags.
I recommend using some method of backing up your Registry before experimenting. I made a snapshot with RollbackRX and also used Tweaking.com RegistryBackup before trying it. So far it seems to make the taskbar population snappier(I have a triple row of icons in my Taskbar.)
For freeware it looks like something kind of fun. It is touted as a privacy utility since supposedly the Registry has this info of deleted folders and the names of the folders might give some clue what programs you were running or something. But I think the shell optimization effect may be more useful in the real world.
I have only done one clean and optimization. But so far things seem better than before running it. But I do have my backups if weird stuff happens.