a couple of years ago i bought the ediamx ew-7218 card for my pc, and had been really satisfied with it, up until two months ago, when it randomly started to disconnect. i would be surfing the net normally, and then try to load a website, and it just wouldn't. moments later, i would get the warning sign on my link icon in the status bar.
to resolve this, i would just disconnect from my net, and moments later, reconnect successfully.
but it just became worse, to the point where it just wouldn't reconnect back to my network.
i though it might be a faulty card, so i borrowed an edimax ew-7628 MIMO card from my friend.
it too worked great untill about two weeks ago, it too started to show the same symptoms like the one before.
i checked the rest of the pc's in my house, and none have been affected with the problem i'm having.
the only possibilities i'm left with are:
1) my motherboard has some problem on the PCI bus.
You are looking at the cards to be the problem, I haven't heard anything about the router. I work with 100's of routers. Some work well for a while, then they have issues. I haven't needed to replace the adapters in my machines, but I had to replace a lot of routers.
A couple things to look for:
Distance from the adapter to the router.
Proximity to neighbors
Try changing the channel on the router
Scan the area for other wireless devices - maybe someone added a new router or there are more wireless devices now.
Interference from microwaves and 2.4 and 5.0 ghz phones as well. No joke, they can really mess the signals up. Your neighbors could have one.