Computer Doesn't Recognize Arduino Uno

So on my old computer running Windows Vista 32-bit I was using my Arduino Uno with no problems, now with my new laptop running either Windows 7 64-bit or Ubuntu 12.04 64-bit, my Arduino won't connect at all in either OS. The first time I plugged it in I got a "driver not found" message, which I expected, but then the device didn't show up in My Computer, and the computer has ignored it ever since. I don't know what to do because I have no way to even troubleshoot since I can't connect it to the computer. I'm 97% positive that I have not damaged it, I've done only small scale projects and the board has never malfunctioned up to this point. Hopefully there's something I can do because I really don't want to buy another one.

Thanks for the help.

bigfish:
So on my old computer running Windows Vista 32-bit I was using my Arduino Uno with no problems, now with my new laptop running either Windows 7 64-bit or Ubuntu 12.04 64-bit, my Arduino won't connect at all in either OS. The first time I plugged it in I got a "driver not found" message, which I expected, but then the device didn't show up in My Computer, and the computer has ignored it ever since. I don't know what to do because I have no way to even troubleshoot since I can't connect it to the computer. I'm 97% positive that I have not damaged it, I've done only small scale projects and the board has never malfunctioned up to this point. Hopefully there's something I can do because I really don't want to buy another one.

Thanks for the help.

You hear something in Windows? like "error"?