I have a win7 and a linux system on my Thinkpad E520. The win7's new work used to work normally. However, 2 weeks ago in the afternoon, the Dhcp suddenly couldn't be started and I lost all method of connection to the Internet(cable & wireless, It even was normal in that morning)....I tried the linux system and find that it can access the internet normally which meant that the network cards were both functioning well. I have discussed this with others in another thread where I found the same topic in this forum. However, this problem is still not solved. This is the link to the thread where I have been discussing with others for 2 weeks: http://answers.microsoft.com/thread/1b6787e2-7b8a-4b3a-b0ed-1e48a4db7468 ======================================================================== I found http://social.technet.microsoft.com/Forums/en-US/w7itpronetworking/thread/d08c8253-51a8-444a-84bb-49b708446745 may has the possible cause of the problem: It seems that the Win7's latest update is not compatible with the BIOS. In the link I provided it seems that it is the Dell that is not compatible with the Win7...Probably in my case it is the Thinkpad E520 that is incompatible with Win7

What type of DHCP do you have? Are there any logs from DHCP? Basic test is ipconfig /release ipconfig /renew Try to reset winsock and reinstall network drivers. Regards Milos

What type of DHCP do you have? Are there any logs from DHCP? Basic test is ipconfig /release ipconfig /renew Try to reset winsock and reinstall network drivers. Regards Milos

I don't know what type it is...I exported the log before. This is the link. https://skydrive.live.com/redir?resid=B12DD090DEA1277D!118&authkey=!AEZpThmyEcI7MyU I tried reset winsock and reinstall network drivers before and they just didn't work. While the basic tests all failed and it said: //ipconfig/release An error occurred while releasing interface Wireless Network Connection: The RPC server is unavailable. An error occurred while releasing interface Local Area Connection: The RPC server is unavailable. //ipconfig/renew An error occurred while renewing interface Wireless Network Connection: The RPC server is unavailable. An error occurred while renewing interface Local Area Connection: The RPC server is unavailable. Roger

I don't know what type it is...I exported the log before. This is the link. https://skydrive.live.com/redir?resid=B12DD090DEA1277D!118&authkey=!AEZpThmyEcI7MyU I tried reset winsock and reinstall network drivers before and they just didn't work. While the basic tests all failed and it said: //ipconfig/release An error occurred while releasing interface Wireless Network Connection: The RPC server is unavailable. An error occurred while releasing interface Local Area Connection: The RPC server is unavailable. //ipconfig/renew An error occurred while renewing interface Wireless Network Connection: The RPC server is unavailable. An error occurred while renewing interface Local Area Connection: The RPC server is unavailable. Roger

Hi, Have you tried to uninstall NIC driver and reinstall it for a test? Sometimes, this is caused by TCP/IP stack can't bind a network address to a TCP socket.Juke Chou TechNet Community Support

Hi, Have you tried to uninstall NIC driver and reinstall it for a test? Sometimes, this is caused by TCP/IP stack can't bind a network address to a TCP socket.Juke Chou TechNet Community Support

1. Would you start service Remote Procedure Call and restart computer. 2. RPC troubleshooting http://social.technet.microsoft.com/wiki/contents/articles/4494.troubleshooting-the-rpc-server-is-unavailable.aspx 3. I would appreciate if you could specify your DHCP server, it is build in DHCP in ADSL router, or DPCP role on Windows 2008 R2,or something else.... 4. Not directly connected with this problem, but test your installation sfc /scannow Regards Milos

Actually, I uninstalled my wireless adapter(Intel Wifi Link 1000) and re-installed it just now. But it doesn't work still...Actually all my connections went down at the same time...Not only the wireless one..So I don't think it is its problemRoger

Actually, I uninstalled my wireless adapter(Intel Wifi Link 1000) and re-installed it just now. But it doesn't work still...Actually all my connections went down at the same time...Not only the wireless one..So I don't think it is its problemRoger

Thank you Milos. I am sorry that I can't get the server's type since routers are placed by my university...But i don't think there is anything wrong with them...Other devices can work very well with those infrastructure. Even my linux system on the same machine can access the internet normally. Regards, RogerRoger

I started the all the RPC services and restarted the computer. But it seems that it doesn't work.Roger

Thank you Milos. I am sorry that I can't get the server's type since routers are placed by my university...But i don't think there is anything wrong with them...Other devices can work very well with those infrastructure. Even my linux system on the same machine can access the internet normally. Regards, RogerRoger

I started the all the RPC services and restarted the computer. But it seems that it doesn't work.Roger

Hi, Do you have any network security tools installed? please temporarily disable them and test again. Also, you can try to export HKLM\System\CurrentControlSet\Services\Dhcp from a working computer, then import it to this problematic box. If it still does not work, please provide the specific error message when you try to start DHCP serivce. Juke Chou TechNet Community Support

Thanks, I have uninstalled my Norton and imported a new HKLM\System\CurrentControlSet\Services\Dhcp to my computer. I restarted the DHCP services but it is the same story. This is massage returned after i typed "net start DHCP" in the cmd The DHCP Client services could not be started. A system error has occurred. System error 5 has occurred. Access is denied.Roger

Thanks, I have uninstalled my Norton and imported a new HKLM\System\CurrentControlSet\Services\Dhcp to my computer. I restarted the DHCP services but it is the same story. This is massage returned after i typed "net start DHCP" in the cmd The DHCP Client services could not be started. A system error has occurred. System error 5 has occurred. Access is denied.Roger

This is the original .reg I exported from my problematic machine. I have changed a lot of permissions according to another person's advice in my old thread. https://skydrive.live.com/redir?resid=B12DD090DEA1277D!146&authkey=!ADf62-XkR9inf_MRoger

This is the original .reg I exported from my problematic machine. I have changed a lot of permissions according to another person's advice in my old thread. https://skydrive.live.com/redir?resid=B12DD090DEA1277D!146&authkey=!ADf62-XkR9inf_MRoger

Hi, System error 5 means you do not have proper permission to start a service. This is normally caused by the CMD running with a standard user token. Please make sure you run cmd with administrative priviledge. Juke Chou TechNet Community Support

Hi, System error 5 means you do not have proper permission to start a service. This is normally caused by the CMD running with a standard user token. Please make sure you run cmd with administrative priviledge. Juke Chou TechNet Community Support

Thanks Chou I am running my Win7 Ultimate as the super administrator. So I am really confused with what has happened.Roger

Hi, Could that be some kind of bug of the system?Roger

Thanks Chou I am running my Win7 Ultimate as the super administrator. So I am really confused with what has happened.Roger

Hi, Could that be some kind of bug of the system?Roger

Try giving System account and Administrator acount full control on hive HKLM\System\CurrentControlSet\Services\Dhcp. Also, you may utilize Process Monitor to check the denied actions. Juke Chou TechNet Community Support

Try giving System account and Administrator acount full control on hive HKLM\System\CurrentControlSet\Services\Dhcp. Also, you may utilize Process Monitor to check the denied actions. Juke Chou TechNet Community Support

I have done that already but it is ineffective.....Anyway, I re-installed the Windows and it is fine now. Thank youRoger

I have done that already but it is ineffective.....Anyway, I re-installed the Windows and it is fine now. Thank youRoger

Try hard coding the IP address in Control Panel\Network and Internet\Network Connections a friend of mine is having the same issue thats why i am here. I am able to hard code the ip information to match my router but i am currently searching for a perm fix. when i find one i will repost. :)

Dear Cordero, I really appreciate your reply. I am also interested in the cause of the problem and the way to solve it(Of course not just reinstall the system). I am looking forward to your findings. Good luck. Best regards, RogerRoger

Dear Cordero, I really appreciate your reply. I am also interested in the cause of the problem and the way to solve it(Of course not just reinstall the system). I am looking forward to your findings. Good luck. Best regards, RogerRoger