For some time, I've been somewhat irritated by slow displaying of the first folder displayed after booting the system which I tend to do daily. It didn't seem to matter what folder. Whatever one was first accessed. After that things would be OK until the next system boot.
I'd see Reading Folder, I think it was, along with the moving green bar. It was a minor enough problem that I hadn't bothered to do anything about it, but today I decided to spend some with ShellExView. I was somewhat doubtful that I'd find anything, but I did.
For whatever interest it may be, disabling PDF XChange Columns Extension, part of PDF-XChange Editor by Tracker Software has eliminated the undesirable behavior. Whether doing so will eliminate anything else I care about remains to be seen.
I'll report this to Tracker Software as an fyi. Whether it's anything they will be interested in, I have no idea,