I've had this wired modem since 2003 on a Windows XP PC, working on a 2MB inernet connection, and it has stood the test of time.
If the internet connection went suddenly off, it was always the fault of wiring becoming loose or ISP trouble.
For the price it comes for, i's a great product! I was initially advised by my ISP provider to buy the same type of modem at a higher price from them (no surprise there!) or they would be unable to provide tech support, but I don't like wasting money, if I can avoid it (nor soft ISP blackmail) so I decided to stay with Zoom and I haven't regretted it!
I have never needed to call Zoom tech support, so I can't say anything about their service quality.
This modem is not suitable for connecting more than one PC, and is not compatible with Vista, although if you can borrow a Vista compatible modem, and connect to the Internet you can, apparently, download from Zoom a driver update which will make it compatible.
If you need to connect more than one PC to your internet you will need to go for a wireless modem.