Do you have dial-up networking. I found only one reference to the 650F part of the error code:
650 - The Remote Access server is not responding.
http://www.modemsite.com/56k/dunserror.asp
And link here:
http://www.modemsite.com/56k/connectoid.asp
IF you can get into Safe Mode:
It may be that some Services aren't enabled:
Start> Run> services.msc>> look for the following Services and right click> Properties on each:
Remote Procedure Call (RPC_> set Startup to Automatic
Remote Access Auto-Connection Manager> set to Manual
Routing & Remote Access> set to Manual
Server> set to Automatic
Computer Browser> set to Manual
RPC Locator> set to Manual
Reboot the computer.
I'm reaching here due to lack of information, but these settings may help and won't hurt.