Internet bugging out (ethernet problem?)

This has happens every once in a while: I will lose internet connection to my computer for sever hours, sometimes a whole day, while another computer on the same network has no problems. I first suspected my ethernet cable was the culprit, replaced it with a new one and the problem remained. Now I'm beginning to think that the ethernet port on my motherboard is the problem. I checked the Device Manager for driver issues and everything seems to be fine (no yellow question marks or X's). Today my computer seems to be connecting without any issues but I'm wondering what I can do to prevent the problem from returning later on. I was thinking about buying a separate ethernet card. What are your thoughts?


My specs:

amd 64x2 4200
DFI Ultra-D mobo
Comcast high speed internet
Nvidia 7900 gt
2 gigs of corsair DDR RAM

 

If the other pc works can you temporarily transfer its nic card to your pc as a test?

 

Good thinking plodr!