install AutoGordianKnot.2.40 avisynth.dll will not install

[zaphod_beeblebrox]

Downloaded and installed AutoGordianKnot.2.40, when avisynth instalation stalls with the message "cannot copy avisynth.dll to system directory" checked what may have been using this dll file, nothing, closed down absolutely anything that may cause problems, browser etc etc. problem persists even after removing every reference to avisynth in the registry, no earlier versions installed.
xp sp2
Thanks

[foxyshadis]

You probably installed SUPER at some point, it causes these problems. AGK is still using avisynth 2.56, which doesn't have the newer installer to work around SUPER's idiocy - making avisynth.dll read only/hidden/system (along with a number of other files, like CoreAVC). Just delete the existing avisynth.dll (you'll have to turn on hidden/system file view) and reinstall.