by Pieter van der Hijden.
Yes, annoying, I had the same problems two months ago. Apparently it is a bug in the XAMPP packaging, see bug tracker: https://tracker.moodle.org/browse/MDL-45595.
There are some workarounds already. The simplest one, I saw a few minutes ago: https://moodle.org/mod/forum/discuss.php?d=245677#p1065538.