My Laggy Server

I am currently using my PC as a web server and a Half-Life dedicated server and I am experiencing some Laggy problem when hosting a dedicated server.

Is it the ISP that matters the internet speed or do I have to upgrade some hardware components in order to overcome this problem... (RAM..)

well I would recommend a minimum of 512mb of ram for a server, a gig of ram would be even better......the other thing is your upload speed on your internet connection. some connections are like 640K DL/256k UL.....but an upload of 640 or better would help.

where can i check the UL and DL speed?