That might indeed be a driver
problem, but it can also be caused by many other things too. If your friend did something "techy" to diagnose the issue, you should get him to write up a couple of sentences here so that others can try to help you based on that info.
- Try downloading the latest _Vista_ drivers
for your NIC.
- Bring up the Task Manager (ctrl+shift+esc) and watch the processor utilisation on your machine for a while. Does it spike up to 100% or near it during one of these "lag spikes"?
- Test what happens in other games. Is it limited to one game only?
- Try booting to "safe mode + net" and playing The Game from there, if it works. Does that make a difference? Does it work without these "lag spikes"?