I can reproduce FS corruption here with reactOS 0.4 RC-1
with almost 100% certainty by performing these steps:
install Winamp5.666 with default settings.
When Winamp starts for the first time system will hang/BSOD.
After restart I always have a
folder full of crap that can't be deleted.
It is important that "Media Library" is selected during setup to not hide this tickets issue.
It is recommended to deselect "UI interface extensions" to hide
CORE-10774 while investigating this.