I dunno, I have a vast amount of em, and at random times I'll have problems with things not working for some reason despite me not having touched them as far as I can recall, so I end up having no idea what the problem is, and especially when something is untranslated/old there's basically no help to find for those things, least for me.
Like for awhile now, I've had Shin Koihime Musou Moeshouden installed and it worked perfectly at one point, however I never got around to getting into it. Course when I decide to finally tackle it, dang thing wouldn't even open, kept getting some sort of runtime error. Ended up reinstalling it a few times, somehow that fixed it and I honestly don't know why it didn't work the first reinstall, didn't change anything, but eh.
At one point I ran CCleaner, and it actually decided that a VN I had was garbage, spared the saves at least... Comp stuff is just so sensitive I suppose.