Have a look here:
Hi everybody I just installed bit-defender it worked well for 2-3 days the there was this error message that would come up the message said
"bit defender Services are not responding"
"The Bit defender Security service (vsserv.exe)is unavailable at the moment. please restart your computer. if the problem still persists,please contact the Bit defender Support team by clicking the support link" how can I fix this Problem?
The error looked like this:
This is my system information:
I use a nvidia graphic card