How do I repair DHCP and related networking after apparent virus damage?

Originally posted at Microsoft Answers, but was told this was too technical for their forum and I was directed here:

A client netbook with Windows XP no longer connects to the internet. The client doesn't recall anything strange occurring just before she started noticing this. The strange thing is it can still connect to a wireless network. When I try to see the IP settings using IPCONFIG, I get the following message:

"Windows IP Configuration

An Internal error occured: The request is not supported.

Please contact Microsoft Product Support Services for further help.

Additional information: Unable to query host name."

That lead me to check the services and found that DHCP service is not running. When I try to start it, I get:

"Could not start DHCP Client services on Local Computer.

Error 1068: The dependency service or group failed to start. "

I tried following the steps in this post as best I could substituting UBCD4Win on USB for the Windows Install disk, but it didn't solve the problem: http://answers.microsoft.com/en-us/windows/forum/windows_xp-networking/dhcp-client-wont-start-due-to-dependency/91d41140-663f-4f58-9a04-9eaab2c40884?page=1&tm=1324426276627

I've checked the dependencies of DHCP in the registry as well as in the properties window and everything checks out: AFD, NetBios over Tcpip, and TCP/IP Protocol Driver.

Some other things I've tried:

• Ran Microsoft Security Essentials full scan (found nothing)
  
• Installed and ran Malwarebytes scan (found three threats and removed them)
  
• Ran SFC (found nothing out of whack)
  
• Uninstalled the affected Non-Plug and Play Drivers
  

Any ideas?

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