When you say "no internet at all" does that include no email?
Have you tried un-plugging and restarting your router/modem? Have you contacted your ISP?
Have you tried booting from your install DVD and running Disk Repair and Repair Permissions?
Try this Troubleshooting Guide for possible tips. I know it says for OS 10.6 and above, and you're using OS 10.5.8, but most of it should apply.
Edited message to put the link in.
i have restarted the isp's router, the weird thing is that i've got full bars on wi-fi, there no internet, then through ethernet while turning off wi-fi with the same modem, still no internet, simultaneusly i use my iphone 5, and other ios devices and 2 pc's in that wifi network working flawlesly, so the modem isn't the problem,
interestingly enough, i have had the chance to play keynotes from the apple website or any other video there, and while i cant perform any other web activity, videos on the apple website run from start to end but can't do anything else.
peering within the home network is posible, i just recently moved my whole itunes library to a newer pc, since my imac doesnt support the latest itunes version mandatory for iphone 5 sync, over 200gb through ethernet
still that dvd option i haven't tried because i lost the disc
I can only imagine one last option, that is replacing my current drive which i upgraded from the one that came from the factory, which was working perfectly in every way when i last used it.
That's why i asked earlier if mine was a recurring problem that could be easily fixed by deleting a file or editing something.
thanks for your help