Microsoft has re-released a 300-page guide to Windows Vista that was posted and then pulled in April. But even though there's now a link to it, Microsoft still seems to be working pretty hard to keep it a secret: it's available in two formats -- a 60-megabyte Word file, and an XPS file. (A what file?)A 60-megabyte Word file download sounds like a pretty successful distribution-prevention strategy all by itself. But it may be a sort of stealth validation test: if your PC is capable of downloading, storing, and displaying a 60-megabyte Word file about Vista, it might be capable of actually running Vista.

The XPS version of the guide is smaller -- a lot smaller -- at 12.2MB. If you're asking yourself, "What's XPS?" you're not alone. The XML Paper Specification (XPS), codenamed "Metro," is Microsoft's PDF-killer. Office 12 applications -- Word, Excel, PowerPoint, Access, Publisher, Visio, OneNote, and InfoPath -- will include a "Save As XPS" option. Windows Vista will include an XPS reader, just like you need the Adobe Reader to open PDF files.

You can download the XPS reader the Microsoft Web site. Just don't search for "XPS reader." That's another part of the distribution-prevention strategy. You get zero hits. Instead search for "XPS viewer." Or just go here and download the Microsoft XML Paper Specification Essentials Pack Version 1.0 Beta 1, all 1.4MB of it. You will, of course, need a Windows XP system patched to Service Pack 4 in order to install the reader -- see Paragraph 2 above.

You can get the full 300 pages of the "Windows Vista Product Guide" here.

Of course, after all this, you may not be able to get Beta 2 of Windows Vista. It was released only to IT professionals and developers with MSDN and TechNet subscriptions. A wider distribution of Vista, called Windows Vista Customer Preview Program (CPP), will be opened "in the coming weeks," according to Microsoft. Microsoft says it anticipates as many as 2 million will test drive Vista Beta 2 in the CPP.

That may be 2 million more people than ever see the "Windows Vista Product Guide."