From: timsuth@... (Tim Sutherland)
Date: 2004-11-12T07:08:29+09:00
Subject: Re: How to "open" a file in its default application - Windows XP

In article <2vi1h8F2l7domU1@uni-berlin.de>, Florian Gross wrote:
>itsme213 wrote:
>
>>>>How do I open a file in its default windows application on XP?
>>>system("#{filename}") should do it, IIRC
>> That would make sense, but it does nothing. Return value is false.
>
>Try using system("start", filename) instead.

As an alternative, the ShellExecute win32 function 
http://msdn.microsoft.com/library/en-us/shellcc/platform/shell/reference/functions/shellexecute.asp

takes a filename and a verb (such as "open") and does what you want.

You could use ruby-dl to access it.