connection suddenly lost HELP!!

so i was on this site, reading,... and running trying to figure out this prt scr button on my keyboard and edit the picture i get from it. when all of a sudden i go to web page click on link and no go. .... i turn and look at my router (MN500) and notice that the port #4 (the one my box is pluged into) is no longer lit. my other puter with a wireless card (mn520ithink) and the power and wireless activity lights are both off on the network card, and the net isn't working on there either ... ...

so i POWERCYCLE(shut power off and leave off for about 5 minutes then turn on from wall jack out, giveing the modem 1 min to power up before turning router on) still no go. i restart both systems (laptop and box) and the laptop is back up. i can connect and am now useing it to post.

the router is not even picking up my puter at all, so i can't access it even in workgroup. windows says that my NIC card is working fine.

my box=
Microsoft Windows XP personal (home edition)
CPU= Intel Pentium IIIE 700 MHz
Network Adapter = Realtek RTL8139 Family PCI fast ethernet
(allso have a HSP56 Micromodem) haven't used for a few years

what else may you need to know?
i am on a DSL connection useing
efficient networks 5100 speedstream modem
microsoft MN500 4 port/ wireless router.

roomates mac in port 1 connects fine.
have tryed differant cord in differant port. no go.

what do U think? help is loved
need more info just ask me?

 

try making sure all cables are plugged in... maybe you bumped something... also, is the network secure? if it isn't, someone might have gotten on the router and had some fun.

 

i made so sure all cables pluged in that i changed out iethernet cords and ports i used on the router.

i was worried about network not being secure, i use the firewall on the router
i use software firewalls on all computers on the network (except mac which i dont' touch cause not mine) i use mac filtering as well. and wireless security (128 bit) update all my stuff as much as i can,
... what is secure? i make things as secure as i know how. i don't think it was something like a hacker.

it is weird it kicked my laptop on wireless offline as well, i restarted and that (twice) and after the second time i got online fine. (ran all the security stuff i could right away, found nothing.

it was a little scarey but i took out my network card from the box, and pluged it back in, the router picked it up for a moment and now it blinks on and off on and off,

network cable not connected, then its fine, network cable not connected

i think my damnd card is bad, but not sure