I'm running on win7 if that's relevant.
You can configure what default directory is used when you start browsing for quest, this is a good feature but I have experienced issues with it for some time. By default ZC uses it's own folder as default browsing folder, and for the most part this works fine. However this is only really defined once: when you set-up the program the first time. This makes sense.., but it has some downsides. For example on my current rig the HDD I have ZC on is carried over from the last rig, but it's not using the same virtual disc slot as it did on my last one. Previously it was on the D:\ disk, now it's on the F:\ disk. Since that place obviously don't exist on the D:\ disk anymore, browsing for quests becomes bit of a chore, good thing you can set up a new default quest directory path!
...Except when you can't. Setting it up works fine, closing ZC entirely and starting it up again and, bam, it works just fine. However, the configuration is lost when ZC crashes (or is shut down incorrectly), even if you didn't set it up in the current session. And in my case that means it defaults back to something that doesn't exist on the D:\ disk. Given that I generally just leave programs running (especially ZC since it's rather light weight), this comes up surprisingly often for me. (Either because the ZC crashed for some reason, or the PC got a BSoD, etc).
This can lead to some rather annoying issues, like having to re-set it again, and:
Purple is the file path of the old install folder.
Green is the path from the new quest folder I defined.
This is not a big issue on it's own, setting up the default quest folder path again solves it, but it does seem like weird behaviour to me anyway, to define quest file paths like this instead of the complete thing from root (or whatever it's called on windows). (I guess it might be convenient if you move the quest folder? Regardless, it's a tangent).