It happened for me, when I uninstalled vista sp1. Reinstalling sp1 fixed the problem.

From devmgmt.msc, view, show hidden devices, under the network adapters, verify if you have multiple entry of isatap adaptor. Try to remove the duplicate one to see if it help.

 

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Thanks for the reply Tijaune

 

I did what you said and I found the hidden devices under Network Adapters.  The following includes all the ones that use the same driver:

 

 

isatap.{A1C6E844-527D-448B-B006-4C7B41FB5791}

isatap.{B3614D7E-A24D-4C44-8DCC-9F9015E3A28B}

isatap.maine.rr.com

Microsoft ISATAP Adapter #3

 

The last one being the one that comes up not able to load driver.

 

Does not seem to be any duplicates.   

I found this which seems to apply to this situation.  I guess there will be an update someday. 

 

http://support.microsoft.com/default.aspx/kb/932520