Hi Joe,
Thank you very much for your reply. I did notice just after I posted this message that the 82579LM is an OEM adapter that is supported by the system manufacturer. I went on the Lenovo site and noticed that they don't even have a driver for Windows 8 for my laptop model!!! I had been updating my driver using the Intel Driver Update utility on this web site so was unaware of the Lenovo deficiency.
I updated to the driver you provided the link for and surprisingly the actual driver version of the NIC is the same (12.6.45.0) but the version of PROSet (18.4.59.0) may be newer (I didn't take notice of the version of PROSet I had previously unfortunately).
After installing this newer version of PROset my system ran for 30 mins without any DPC spikes. In the last hour of testing (with Audio running in my DAW full time) I have only had 2 DPC spikes which have dropped out the audio, so it is MUCH better, but the problem still exists. Hopefully Lenovo can release a Windows 8 driver, or hopefully one of the next generic drivers from Intel will fix the issue.
Thanks again for your help,
Brad
