I'm updating TL on a Mac (System 10.6.7) and tlmgr want's to appreg texworks.exe 2011-05-07 07:14:28 +0200 Error tlu_ipctask[6636] do_postaction: don't know how to do appreg prog="texworks.exe" cmd='"TEXDIR/bin/win32/texworks.exe" "%1"' exts='.tex|.sty|.cls' It didn't install the binary. Maybe the postaction should be limited to Windows. Axel