steampowered.com get the client and you can get 1.6 cs version from there.
You need a computer that can run Half-Life 1From Wikipedia:System requirements Windows 95, 98 or NT; Pentium 133 (166+ recommended); 24 MBRAM (32 recommended); mouse; keyboard; 640x480 SVGA high color (16-bit) display; Windows-compatible sound device; 400 MB hard drive space; 3D accelerator card recommendedThis besides the obvious good internet connection, you will need a copy of Half-Life 1 installed because Counter Strike is a mod of it.
Da Strike was created on 1994-12-16.
The Hunger Strike was created on 2008-03-16.
Crime Strike - 1999 2011-12-16 was released on: USA: 16 December 2011
Strike It Rich - 1951 1954-02-16 was released on: USA: 16 February 1954
Crime Strike - 1999 2013-09-16 was released on: USA: 16 September 2013
Crime Strike - 1999 2013-12-16 was released on: USA: 16 December 2013
Crime Strike - 1999 2012-03-16 was released on: USA: 16 March 2012
Crime Strike - 1999 2012-04-16 was released on: USA: 16 April 2012
Crime Strike - 1999 2012-07-16 was released on: USA: 16 July 2012
Air Strike - 2004 V is rated/received certificates of: Germany:16 (cut) Iceland:16 Netherlands:16 Singapore:NC-16 USA:R
The Strike - 1912 was released on: USA: 16 August 1912