[wolkow70]

Сам нашел такой вариант:

StrCpy $0 "$PROGRAMFILES\FinalWire"
Call un.DeleteDirIfEmpty

Function un.DeleteDirIfEmpty
FindFirst $R0 $R1 "$0\*.*"
strcmp $R1 "." 0 NoDelete
FindNext $R0 $R1
strcmp $R1 ".." 0 NoDelete
ClearErrors
FindNext $R0 $R1
IfErrors 0 NoDelete
FindClose $R0
Sleep 1000
RMDir "$0"
NoDelete:
FindClose $R0
FunctionEnd