I agree with BadDog – it’s a major Lame Tech Excuse. The guy didn’t know how to fix it, so he just blamed the problem on your computer.
When you say, “couldn’t get the modem synched” – what exactly did you mean by this? For example, my cable modem has some lights labelled “Receive”, “Send”, and “Online”. When I first plug it in, the lights will blink, and the blinking light means it’s trying to acquire a channel (e.g. when the receive light blinks, it’s trying to acquire the receive channel). Once everything is connected, all three lights are ON, solid.
Now, when you say can’t get the modeml synched, did this mean that the modem didn’t seem to be making a connection? I don’t know your model of modem, but I presume there would be some indicator lights on the front to tell you whether it had acquired a connection or not – did it?
If NOT, then it would have nothing to do with your computer – it would be the cable modem or the cable line itself.
When I first got my cable modem, everything else installed, I got the ethernet driver installed (with some trouble, because the Win 98SE’s “Add New Hardware” wizard is basically worthless when it comes to searching for drivers, and can’t tell its own ass from a hole in the ground). However, my first attempt resulted in the lights on the modem blinking and blinking and blinking, and there was never a connection. Turned out to be a problem on the PHYSICAL cable line – they had to replace an old splitter on the outside of my house. The cable TV had been coming through fine, but something about the splitter wasn’t allowing the internet connection to go through.
So, it could be a variety of things. If the cable modem IS acquiring a connection, then I would guess that it’s one of the settings for the network card. You’d get to these, for instance, by going to the “Network” control panel and selecting the appropriate "TCP/IP -> (name of your network card) " item, and selecting “properties”. There are settings relating to dynamic vs. static IP, what protocols it used for DNS, etc. You need to make sure you know what all the settings should be (i.e. your service provider needs to TELL you what the correct settings are).
But if it’s the cable modem itself that is not acquiring the connection – tell them to fix the modem, or get somebody from the cable company to check the line (I’m not sure how this would work in your case – I presume they would have some agreement with the cable company itself…?)