I already posted this question resintly.

But after reading this article
I'm totally confused.

Here are some exerpts:

"For Web servers, the same PC Week tests showed Windows NT 4.0 with
Internet Information Server 4.0 delivers 41 percent better performance
on a single processor system and 125 percent better performance on a
4-way system than Linux and Apache."

"Linux only provides access controls for files and directories.
In contrast, every object in Windows NT, from files to operating
system data structures, has an access control list and its use
can be regulated as appropriate."

"Linux security is all-or-nothing. Administrators cannot delegate
administrative privileges: a user who needs any administrative
capability must be made a full administrator, which compromises
best security practices. In contrast, Windows NT allows an
administrator to delegate privileges at an exceptionally fine-grained level."

And the list goes on...

What do u think about it?
My boss does not interested in costs of these OS,
He wants the securest OS.

Could someone, PLEASE, give me a link to some article which states
which OSs were more sucsessfully hacked ?