Still broken in 0.7.0. Package contains libiconv2.dll but tar.exe at least appears to require libiconv-2.dll (added dash).
Simply renaming libiconv2.dll to libiconv-2.dll appears to resolve the problem.
Sounds like a decent fix :)
Duplicate of #68
This problem still exists in gow-0.7.0 It seems that if you are going to mark this problem fixed you would have renamed libiconv2.dll in the gow-0.7.0.exe so others don't have to continue to deal with the problem of tar.exe (and possibly others) not working properly.
He closed it because it's a duplicate of this one: #68