I have internet access through the cable TV company. I can connect to the modem/router through either an ethernet port and cable or a Brand X wireless card. With the wireless card, I lose my internet for a few seconds every time the phone rings. Huh? Any ideas what is going on? It’s not a big deal, but the 25’ cable snaking its way across the room is a bit unsightly.
I’m assuming you’ve got cordless phones. Many cordless phones (and many other wireless household devices) use the same basic frequency band as most wireless routers: 2.4 GHz.
So when the phone rings, the power between the phone and the base station ramps up, and it interferes with your wireless 802.11 connection.
You can try setting your wireless router to use other channels, it helped in my house. I just tried each channel in turn until I had the least interference.
Failing that, a different wireless card and/or router may handle the interference better.
A different cordless phone would probably be cheaper and easier to replace.
Could be, I haven’t bought a phone in a couple of years.
But the last time I did, I spent about $200 on a good phone set (base station with hands free and answering machine and two handsets with separate charging cradles, caller id everywhere, and various other features). A wireless router and card together are probably less than $75.
Mine does the same thing and I have a hardwired phone. 
I had a nightmare with this. Sometimes it would interfere for a few seconds, other times for hours. Finally it was suggested that I buy a 5.8GHz phone. I did. Problem solved. Do yorself a favor, go get a new phone.
Yeah, 2.4 was declared public, so loads of companies decided to plunk their hardware in it.
If you don’t want to get a new phone, you can change the channel your wireless works at, which will shift the frequency within 2412 MHz to 2462 MHz. (Chart)
Some routers seem to drop wireless LAN connections momentarily if they’ve lost the external wired network - if you’re on ADSL, it could be that a faulty microfilter on your phone line is allowing your modem/router to lose sync when there’s an incoming call and that this is making it drop the wireless access while it re-establishes the connection.
It’s not supposed to be that way (and I’m not saying this must be the case here*), but I’ve seen in on several different ADSL modem/routers.
*-you can test if it is - physically disconnect the router/modem from the phone line and see if the client PC reports loss of the wireless link.