Battling this one for hours on and off. I upgraded my xenserver pool from 5.6 to 6.2. Once complete I booted one of my VMs', upgraded the Xenserver tools and then came to a grinding halt. The Xenserver tools requires a couple of restarts now, The VM (2008r2) was stuck on Applying computer settings" for an age and eventually presented the login screen. However on login I got this:
The only way to get past this was to deactivate the nic from Xencenter, which in itself I took a while to discover. Anyway, nic disabled I got to the desktop and uninstalled, reinstalled and did all I could to get this issue resolved to no avail.
The eventual solution, reset the Network Stack:
Two short commands and issue resolved:
netsh int ip reset C:\netsh.log.txt
netsh winsock reset
On reboot check your NICs as you may need to add the ip address, subnet and gateway again.
Hope I've saved you time :-)