To the best of my knowledge Windows has a vastly more complicated security model (token based security) than Unix . It has no /etc/passwd, stat returns (mostly) useful info, getpwuid() is a stricly unix concept that is meaningless in a win32 context. The equivelent of a group writable file is a file with access permissions deriving from a usergroup. Objects in Win32 can have user level permissions or group level permissions, with fine grained tuning, ie, you can say group X has read, write and execute, group Y has read, group Z has read,write etc. Similarly with users. To the best of my knowledge there is no sticky bit.

I suggest you find a book on Windows administration in general. They are usually written for a low denominator, so all that will happen is that you wont have to read all of the explanations of concepts you are familiar with.

Actually a while back I discovered one of the flaws of the Win32 security model. Its _too_ damn powerful. In order to make it powerful it has to be complex, and by making it complex its really hard to do right, which means that in the end people end up not bothering. Security models should be simply enough that any programmer can be briefed on how to use the model effectively with minimal training. Requiring people to have indepth understanding of a complicated security model just means that people will write insecure code, either because they didnt understand how to secure it properly in the first place or because they didnt bother out of frustration.