>>>Hi all
>>>
>>>I know this might not be the best place but I am curious if there is something I can do about the MAC address to remain constant. I have seen such MAC addresses as below and they keep on changing esp. when the computer is starting up
>>>
>>>DCDCDCDCDCDC
>>>8C8C8C8C8C8C
>>>CCCCCCCCCCCC
>>>
>>>Not sure what I need to do about getting a real MAC address. I have two network cards, one which is on board for LAN use and another one I had to fit extra for my ISP. It is this extra PCIe card for which the MAC address keep on changing.
>>
>>A physical NIC has a hard-coded ("burnt-in") MAC address which looks nothing like your examples above. These are guaranteed to be unique so for most users they never need to be changed. The NIC will have that MAC address at the time the hardware boots.
>>
>>The first thing to check is that the card is OK. Check the support site for the card manufacturer, there are often diagnostic utilities. Also check you have a good cable going back to the switch and that electrical power quality is OK.
>>
>>After the OS boots a NIC's MAC can be changed by software. The most common (and often legitimate) thing that does that is virtualization software. If you're running virtual machines (VMs) it could be related to that.
>>
>>Some advanced network security tools might manipulate a MAC address in order to spoof another host. But, it's unlikely you'd see MAC addresses such as above so that's not likely the cause.
>>
>>The only other thing I can think of is malware. Maybe some malware is hooked into your networking stack and acting as a proxy for the physical NIC so it can scan/record traffic.
>
>Thanks Al, I have put my machine on a full scan, hopefully nothing comes out of it.

A couple of other things you could try:

- Install the card in another computer

- Boot your existing computer with a LiveCD or LiveDVD such as Knoppix, Ubuntu or a utility CD e.g. http://www.gfi.com/blog/top-5-free-rescue-discs-for-your-sys-admin-toolkit/

In each case see what MAC address is reported.

Some of those rescue CDs offer utilities for detecting rootkits and other malware that cannot be removed from within Windows itself.