Dagnabbit! I thought this was a resurrected thread. It is just the same old jumping to conclusions with not enough info.
If you don't want to know how stuff works, then pay someone to do it for you.
<deleted rant concerning imaginary differences between computer brands>
If you want to understand what you're really dealing with, think about how the issues you have are related and how they are unrelated.
The lights on your DSL modem or your comcast "modem" tell you whether you are connected to the internet at a basic level.
Ping and tracert/traceroute from the command line of either OS will tell you whether you are connected to the internet at a meaningful level. (Ip layer, traffic is sent via datagrams addressed to devices with IP addresses.)
Mail servers have ip addresses. If you are using comcast, your smtp server has an ip address. If you are using MSN or most other ISP's your mail server has an ip address. This address is assigned by both comcast and isps.
When you mail does not send you may or may not be connected to the internet. Both Apple mail (depending on version) and Outlook (both) can arbitrarily decide there is some character or whitespace in your email and refuse silently to send it until you correct it. Your wireless connection 3 rooms away can also make your computer think the net is unavailable.
Some older houses (like mine) use plaster and lathe wall construction. This acts like a faraday cage to block signals in the microwave range used by wireless routers. There are ways to test this and ways around this.
A dsl modem can be hooked up anywhere in the house a phone line is available. A cable modem can also be hooked up anyplace a cable tv can. There are ways to optimize weak signals for either type, and the wireless function built into them but may require additional equipment in some house layouts.
Both qwest and comcast will by default, set up your computer in a way that is advantageous to them rather than to you.
In their perfect world each person would pay full price plus extra fees and tax for each computer that is hooked up to the net.
They cannot quite reach that goal as long as there are still users who understand what they are doing.
Most ISP's promise the level of hand holding and "support" you need only where it can not be used as evidence in court. They not only can't, but never intend to actually do so no matter what computer or OS you use.
That said, the basic details needed to connect either Macs, PCs or mobile devices to your ISP is available somewhere on the net if you look hard enough and know what questions to ask.
I could go into more detail if you want to contact me, but we have hashed most of this out before on this forum. Search for comcast or qwest in the box in the upper right to see the previous tales of woe and gnashing of teeth.
I understand the high-school team spirit sort of brand worship that goes on among Mac users and Windows users only in an objective sort of way. I was puzzled by pep rallies in high-school as well.
There is nothing inherently special or magical about either hardware or the software (though Time machine in 10.5.7 and up is very elegant)
I run OSX, windows or linux/BSD on both modern apples and on PC's. I have ancient apples, old pcs and one lonely sparc station stacked in attic or garage piles in case I need them to fix something and I can use or repair any computer. I have no more respect for Apple certification than I do for Windows certs. I have known idiots with either one.
Currently Comcast is lying slightly less than qwest in their ads but how you use the net should determine which setup you use, not the fevered dreams of brand loyalists nor the PR hyperbole of tv ads. The download speed CAN be much faster with comcast, but it depends on what neighborhood you live in. In some cities and even rural areas the speed difference is far greater between dsl and cable.
I have used both and while Comcast is faster, the company is evil incarnate, it quickly fires or promotes away from the phone, any support techs who have a clue or speak english or both. Their way is the only way and every standard bit of networking will cost ya extra if you can ever find a CS rep who will admit to understanding what you want or indeed what the initials of their job description stand for.
Your choice of ISP might mean more than your choice of carrier. Comcast is it's own isp and what you get is what they offer. No exceptions.
Qwest is the DSL transport. The isp choice is what determines what connectivity, latency and services are offered to the customer.
MSN might be a good fit for some but I find it nearly as useless as comcast myself. I use accretive technology mainly because they give me the networking I need, understand routing and otherwise leave me alone.
I also am a former employee so I have everyone's cell phone number. :)
I have special circumstances and run servers and services over mine though. You would probably find the hands off approach I need quite distressing.
So.
Eliminate the possible/probable issues on your side of the wire before blindly hoping a change of carrier will fix the issue.
If you need someone to evaluate and diagnose your problems, my email is under my name above this post.
I do free work for those on public assistance, ss/ssi or unemployment.
All others can donate what they consider fair. My offer is outlined here.
Maybe I should bump it again.
http://westseattleblog.com/blog/forum/topic.php?id=6117