Mahisse :
Go into options and change graphics to Direct3D or OpenGL maybe? Are people still playing this?
eSport scene was alive until to years ago (over 20 huge european/continental tournaments during year, world cyber gaming, over 50 professional teams) when CSGO was released and players were forced to go and play csgo, at least professional ones since all tournaments were transfered into CSGO even though non-professional players didnt like it so much. Even today you can see on steam 15k players online at least and over 30k peaks during one day and on gametracker you can find way to much public servers where are nonsteamers, and usually they were like 2 or even 3x more then people who bought game via steam.
@shivam071, what is your fps ? Did you tried to turn off vsync in gpu settings ? Playing on 60fps capped in 1.6 feeling can be laggy, or it's lag from your internet ? Turn on net_Graph 3 via console and check that info while you are playing.
P.S Are you playing on steam ? Because steam version is now with much higher system requirements then what it was back in early 2000's, same thing for nonsteam version but there were a lot of updates so it's little bit higher even there.