Windows Thin PC: Windows, Slimmed Down

Last month, Microsoft released a Community Technology Preview (CTP, in essence a public beta) of something called Windows Thin PC. This business-oriented operating system’s given purpose is both to allow older,

less-capable PCs take advantage of some of Windows 7’s core features, and to allow cost-conscious organizations the ability to convert existing hardware into thin clients.

Windows Thin PC isn’t actually a new product: it is, more or less, a rebranded version of Windows Embedded Standard 7, an awkwardly named product sold only to OEMs for use in, well, embedded systems: think thin clients, cash registers, and web kiosks, to name a few.

There are two main things that separate Windows Thin PC from Windows Embedded Standard 7: its name (though the Windows Embedded moniker still lingers on in a few places) and its licensing (where Windows Embedded was sold to OEMs only, Windows Thin PC is being made available to Microsoft’s volume licensing customers. Consumers, sadly, can’t get their hands on either OS legally).

While Windows Thin PC isn’t going to be something you deal with unless you work for a thin client-oriented organization heavily invested in Microsoft technology, I wanted to take a close look at the OS to see what techniques it uses to reduce its footprint and resource usage. Windows Thin PC makes a case for a Windows that’s more cloud-friendly and modular than classic fat-client Windows, something that the platform is going to need if Windows needs to run on everything from your monstrous eight-core workstation to your Atom or ARM-powered tablet.
System Requirements and Features

First, let’s talk about the sort of computer that can run Windows Thin PC. This is no “MinWin”-style OS designed to run using just megabytes, but a very Windows 7-like OS system requirements identical to the standard version of the OS. To wit:
Windows Thin PC (32-bit) Windows 7 Ultimate (32-bit)
Processor 1 GHz x86 processor 1 GHz x86 processor
RAM 1 GB RAM 1 GB RAM
Hard disk 16 GB available hard disk space 16 GB available hard disk space
Graphics card DirectX 9 card with WDDM 1.0 driver DirectX 9 card with WDDM 1.0 driver

In practice, the OS needs fewer resources than what’s listed here, but you’re still not going to get this running on the Pentium II box stashed in your attic. Windows Thin PC takes up much less hard drive space than Windows 7, as we'll see later, but in terms of CPU and memory usage it's much more similar. This isn't going to somehow make running Windows on an Atom processor any less of a slog.

The benefit to keeping Windows Thin PC so similar to standard Windows is that businesses already heavily invested in a Microsoft backend – Active Directory, local Windows Update servers, Microsoft’s image development and deployment tools, and the like – can use the same technology they already have to setup, lock down, update, and otherwise manage the OS. Thin PC can also take advantage of the full range of Remote Desktop features, up to and including the recent additions made to the client and server in Windows 7/Server 2008 R2 Service Pack 1.

Another Thin PC feature that can help beleaguered system administrators manage their systems is the Enhanced Write Filter (EWF), a technology that can prevent permanent changes from being made to the OS by the end user. Windows Thin PC can, using a RAMdisk and unpartitioned space on the hard disk, store any write operations that the user makes to the drive. So, in essence, if you save a file to the desktop or install a program, it will be written to the EWF volume instead of the main Windows partition. Since records of these extra files are not stored on the main system partition, the user is presented with a clean OS upon rebooting. This keeps the machines easy-to-fix in the event of spyware or virus infection, with the added benefit of discouraging client-end computing and encouraging users to connect to the remote server to get anything done.

Windows Thin PC also offers some business-oriented Windows features included in the higher-end Windows editions, chief among them the Bitlocker Drive Encryption (only otherwise available in the Ultimate and Enterprise editions), the ability to join Active Directory domains, and the ability to both join and host Remote Desktop connections (both features of all editions Professional and higher).

Computers running Windows Thin PC (as opposed to the full version of Windows) don’t require what Microsoft calls a “Virtual Desktop Access” license to access a remote server – this is good news for cash-strapped businesses looking to thin clients to reduce costs, because a VDA license typically costs $100 per device per year.