I can't play rs?

I just got new high speed internet a couple weeks ago it's Comcast Xfinity. I then hooked it up to my NetGear WNR1000v2 router. I can play xbox 360 and ps3 fine, but when i try to play runescape its extremely laggy and can barely even login. I've opened the ports on the router following a guide. but it still has no major effect any suggestions?

 

Could be your PC. I connecting through Comcast right now and my internet connection is purring like a kitten. How old is the computer?

Routers can cause lag. I don't use a router for that exact reason. You can also try using a public DNS, since some may be faster for you, depending on your area.

 

the PC is a couple years old.