Sambob

Hi, before yesterday afternoon everything was working fine, then i went out and came back in and my brother was complaining that he could not get on world of warcraft and that ventrilo and xbox live were not working (could not connect). I checked my computer and neither WoW, ventrilo, call of duty or teamspeak worked on the internet. However, we could both get onto the standard internet fine, and download things etc. Windows live messenger also works fine. We share an internet connection and have a router as well as both having kaspersky internet security, so i didnt think it would likely be a virus or spyware? This has really confused me and was just wondering if anyone knew what this could be? or how i could fix it? Thanks a lot for your time! Appreciate it :)