Windows 7: Problem with a program slowing my internet connection

Hello. I have 2 computers connected at internet with a router. When one of them is running Sopcast, on the other one internet is working very slow. For example, in online games i have a massive lag and when browsing it takes 2-3 seconds more to load each site. When i ran the program on the site Pingtest.net - The Global Broadband Quality Test, I get results like ping over 100 ms and jitter over 30 ms. What should I do, without turning off sopcast on the other computer?(as there is someone watching TV with it). Thanks in advance!

A ping of under 150 Ms is considered normal whats your network setup like? Wifi, router, modem, etc.

What is the ISP supposed to be supplying you with?

I am using modem with router separately, as there is only one place in the modem to put the cable(i mean from modem goes a cable to router, then 2 cables to those 2 computers), and my internet speed is 20 Mb/s. I just ran the test on pingtest.net, and it showed 313 ms ping and 367 jitter. Waiting for a future reply and thanks in advance

OK and the connection, is it DSL, cable, etc?

313 is somewhaqt high how far away was the speedtest server (it says in the results box)

Cable. I just ran a speedtest and showed 350 ms..And i select Begin Test, which allows the server to search for the fastest ping zone. It displayed a zone close to my residence.

Close?

Hm...now it moves better, but it is still poor:

Ok Ping isnt the issue. Loss means things have to resend packets in 6% of the time.

What is Sopcast?

You may have 12 Mb downlo0ad but your upload may be substantially lower and sopcast (whatever that is) may be hogging the uploads. Run speedtest and find the upload speed with sopcast running and without it.

My upload speed with sopcast is around 1 Mb/s, and my provider offer was 2 Mb/s.

Sounds like your Sopcast is being used outside your network. If some one or as many as more than 1 is connected to the Sopcast is will effect your Download speed thuss causing high pings. You need upload too be there for Download to work.