With Microsoft Windows having such a large market share, how could you have a complete portfolio without working with it.

Workstation Management
I have been working with Windows since the beginning.  I have worked with Windows 3.0 all the way to Windows XP/2003 (and soon to include Vista as well).  I have managed older NT server using netshare and Policy Editor all the way to Windows 2003 server with Active Directory and Group Policy. 

SYSPREP
Group Policy / Policy Editor
Software Update Services (SUS)

Favorite Tools
Cygwin
Cygwin + OpenSSH + RSync make great additions to a Windows workstation or server.  These products together give you the same features you have on you Linux servers with SFTP and SCP file access and the ability to use RSync for backups.  As well as you get great tools to use for parsing those long log files into a more manageable form.

OpenVPN
The easy of use, speed, and ability for remote client configurations makes OpenVPN my favorite solution for VPN access into remote networks.  I even use it to encrypt my data over shared networks such as hubs or waps for added security.  Also the ability to choose between the VPN being the default gateway or just another route is another great feature.

Programming
Every time I get in a tight spot and don't have quite the utility I need, I just sit down and program one. 

Visual Basic (3 to .Net 2005)
Visual Studio (6 to .Net 2005)
Active Service Pages (ASP vbscript)
Visual Basic for Applications (Excel, Access)

Servers
NT 4.0 Terminal Server
Using Windows NT 4.0 TS I managed a lab of 30+ computers.  Terminal Services was mainly used from a remote administration point of view.  Login scripts and policies were used in this lab to control access and workstation configurations.  I also managed remote workstation install of Windows 3.11, 95, and 98.

2003 Advanced Server
With Windows 2003 Server I have configured several web servers using IIS and MS SQL .  I have had experience with integrating Active Directory to e-Directory using DirXML.  I have also configured and managed Terminal Services as a remote access point of presence into a secured network, granting users the same look and feel at home that they would have from the desks in their offices.