I also had no internet/network - ipconfig wasn't recognized and returned an error etc etc
I tried EVERYTHING for 3 days straight - all microsoft reset fixes, 3rd party ip fixing software - EVERYTHING.
I eventually found how to fix this problem + I was kicking myself how simple it was - spyware/virus had changed the tcpip.sys file and had some mechanism to resist attempts to fix the issue, so just delete tcpip.sys in system32/drivers AND the spyware backup file (of the same name but different file extention) the original circa 2004 tcpip.sys circa 2004 will automatically appear and everything will work.
SIMPLE!!!!!
Hugo
ps next run the best antivirus-spyware you can find to get rid of anything else left behind