Check for incompatible software:
Maybe BullGuard firewall
Post a HijackThis log.
Download it here: https://sourceforge.net/projects/hjt/files/2.0.5 beta/HijackThis.exe/download
Run HijackThis as Administrator, click on "I accept", then "Do a system scan and save a log file".
Then a text file will open. Copy everything, then paste it on https://paste.ubuntu.com and give us the link.
While it does sound scary, it does not give us any personal or sensitive information.