Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
@echo off
cls
texconv -w 1024 -h 1024 -m 8 -f DXT5 *_t.dds
@echo off
cls
texconv -w 1024 -h 1024 -m 1 -f DXT5 *spec.dds
@echo off
cls
texconv -w 1024 -h 1024 -m 1 -f DXT5 *_t.dds