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Windows 7: MAC address of my LAN card changes at every reboot

21 Nov 2017   #1
romiadam

Windows 7 Home Premium 32bit
 
 
MAC address of my LAN card changes at every reboot

LAN card: Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20)
Laptop: ASUS U50VG

To make sure this is not an issue of the OS (Win7 HP 32bit) I installed a fresh windows. No drivers, no any updates, Windows not registered.

As the win7 instalation has finished, I checked the LAN card in the Device manager. It was installed successfully and it wored (connected to internet via LAN card). It already had a number #2 (Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #2

Problem:
Always when I reboot the windows, the LAN card is installed again and there is added number as #2, #3, ...
Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #2
Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #3
Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #4
Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #5 and so on.....

I find out that the MAC address of my LAN card is always different after reboot. This must be the issue.
The Wifi card and Bluetooth MAC address is always the same.

Moreover thare are added always new entries in to the registry (subfolders as 0001, 0002, 0003, ... and so on)
On my 2 year old windows system there is 550 entries (subfolders in the registry - 550 unnecessary entries).

If I change the MAC address of my LAN card in the device manager (Advanced), than DISABLE/ENABLE the LAN card, the ipconfig or getmac command in CMD shows my MAC address, what I entered in the device manager. In the registry there is enrty NetworkAddress (my entered MAC address). So it is there.

But If I reboot the windows again, and previously (before restart) my LAN card was installed as e.g. Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #15 with changed my own MAC address in the device manager,
after reboot the card is installed agai, as
Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #16
The MAC addres is not the same as I entered in the device manager before restart, in Device manager the MAC address window is empty, in registry there is added a new subfolder entry e.g. 0024 for new card named Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20) #16, if I open it there is no entry NetworkAddress.
The entry NetworkAddress is it the subfolder 0023, and that MAC match with my own entered MAC address in device managerbefore restart.

So at every reboot windows is loosing any information about previously installed LAN card, the LAN card is installed again. In the device manager the number #xy is increasing at every reboot. The new entries are added in to registry at every reboot.

Moreover I installed in to my laptop WinVista HP and this happened there too. The same issue.

Can anybody explain this issue with my internal LAN card? I can not replace it (as I know).
Is there any option to get rid of this issue?
Is my LAN card faulty (it works normaly, only MAC is changing)
Can I stop in the Win7 instaling only the LAN card? I need to install another devices when they are pluged in to USB.

I have contacted the ASUS technical support. We ended up that I have to send them my laptop for diagnostics. It does not worth me, due to this laptop has few years (5-6). It is still working well. It has just this MAC address issue.

Thanks a lot to all for repply.


My System SpecsSystem Spec
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21 Nov 2017   #2
mrjimphelps

Linux Mint 18.2 xfce 64-bit (VMWare host) / Windows 8.1 Pro 32-bit (VMWare guest)
 
 

Does the problem continue if you boot to Linux?

To test this, create a Linux DVD (www.linuxmint.com) and then boot to the DVD. (Doing this will make no changes to your hard drive.) Reboot a few times, to see if the MAC address keeps changing.

If it doesn't change in Linux, then likely the problem is somewhere in Windows -- perhaps this is a Windows registry issue, which wouldn't exist in Linux.

Or maybe the difference in behavior between Linux and Windows could be explained by the fact that when you run Linux from the DVD, no files are changed on your hard drive. In other words, maybe there is a config file that keeps changing when you're in Windows (but not in Linux).
My System SpecsSystem Spec
21 Nov 2017   #3
samuria

win 8 32 bit
 
 

The Mac address is burnt into the firmware and should be unique in the world the only reason I can think of it being changed is it had the same number as another device some ISP tie it to your connection wonder if that is changing it
My System SpecsSystem Spec
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21 Nov 2017   #4
romiadam

Windows 7 Home Premium 32bit
 
 

Thanks for repply.

mrjimphelps:
I do not have now time to try it in the LINUX. I have one LINUX installtion CD/DVD. I will try it later at weekend. But I do not know how to check the MAC in LINUX. 0% experiences with LINUX.

samuria:
The computer is not connected to internet (router) thus ISP can not change MAC address.



Just few minutes ago I have finished the WinXP installation (writing this post from WinXP via LAN card connection. So the LAN card 100% works).

As the WinXP installation has finished, the LAN card in WinXP was not recognized (yellow question and exclamation mark). I installed the LAN card driver for WinXP from memory stick. In device manager there was LAN card named as: Atheros AR8131 PCI-E Gigabit Ethernet Controller.
I rebooted the computer 3 times. The LAN card was not installed and in device manager, the LAN card name has not changed (there was not added any number with this mark #) GOOD sign.
But the MAC address has changed at every reboot as:
00-00-B3-37-16-00
00-00-BD-5D-16-00
00-00-11-79-16-00
00-00-CB-7F-16-00

As you can see only two pair of numbers are changing. (In Win7 there changes three pairs of numbers marked as XX MAC in Win7 00-00-XX-XX-XX-00)

Than I manually changed the MAC in device manager to 00-00-B3-37-16-00. In the registry there was added entry NetworkAddress 0000B3371600. After reboot, the MAC address was not changed. It was again 00-00-B3-37-16-00. So the WinXP holds the manually entered MAC address and reads it from registry. I think that because the network card is not installed again after reboot and in the registry is not added a new entry at reboot. Strange.....


Because this MAC address issue is happening in Win7, WinVista and WinXP, I am pretty sure that the reading the MAC address from LAN card fails for some reason. Ther MAC address readin might be the issue.

If I can get this in Win7, that the Windows will hold manually entered MAC address, I will be happy.
I am going to do one more fresh Win7 install and see if the LAN card will reinstal again at every reboot. I will let you know.

Any suggestions how to turn off LAN card installation in Win7 if it will be installed at every reboot?

I searched google. I could not find any utility for LAN card diagnostic in Win7. Is there any utility in LINUX? I would like try to read MAC from LAN card. I am curious if it will fail with error or it will read it...???
My System SpecsSystem Spec
21 Nov 2017   #5
DMHolt57

Win7 Home Premium x64 W10Pro&Home
 
 

I found some old posts about this problem, and all were driver version related. Check your version and see if this driver will fix the problem. Download Qualcomm Atheros network driver for AR8131 and 32bit Windows 7
My System SpecsSystem Spec
22 Nov 2017   #6
romiadam

Windows 7 Home Premium 32bit
 
 

DMHolt57
I have tried many different versions of the driver (about 5 versions) , but the driver on your link was most recent. Did not solved the issue.


I did again fresh win 7 installation with disabled LAN card in BIOS. As the win7 was installed I rebooted laptop to BIOS, enabled LAN, and start up win7. The LAN card was installed automatically using Microsoft driver. Than I updated the driver to most recent. The name of LAN card has changed from Atheros AR8131.... to Qualcom Atheros AR8131.... After reboot the LAN card was installed again usin the my recent driver, MAC has changed (as described earier 3 pair digits), LAN card name changed to Qualcom Atheros AR8131......#2. After next reboot Qualcom Atheros AR8131...#3 and so on.

For some reason the LAN card is installed always after reboot.

Now I do not know if first the LAN card is installed and the MAC is issued for this newly installed LAN card (due to the win can not read MAC from the card or whatever reason) or first the MAC is issued and than the LAN card installation starts due to the new MAC.

I changed the MAC in device menager. In md getmac command returned my manually entered MAC. After reboot my manually entered MAC was "ignored" because the LAN card was installed with new number ....#4. In the registry my manually entered MAC was in the entries for ...#3.

Why win7 can not read my MAC from registry and why always reinstall the LAN card?

I am getting hopeless....
My System SpecsSystem Spec
22 Nov 2017   #7
mrjimphelps

Linux Mint 18.2 xfce 64-bit (VMWare host) / Windows 8.1 Pro 32-bit (VMWare guest)
 
 

Quote   Quote: Originally Posted by romiadam View Post
Thanks for repply.

mrjimphelps:
I do not have now time to try it in the LINUX. I have one LINUX installtion CD/DVD. I will try it later at weekend. But I do not know how to check the MAC in LINUX. 0% experiences with LINUX.
In Linux, open a terminal session and type ifconfig [enter]. (This is similar to ipconfig in Windows.)
My System SpecsSystem Spec
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 MAC address of my LAN card changes at every reboot




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