Well i would start from scratch.
First unistall ur bull guard antivirus.Is this the only reason why ur system cannot shutdown properly.
Try to restart a number of times after u done some work.(lets say 5 times ..each time u will do something differnent,copy some files,read a pdf and so on)
The try one of the free antivirus..like
AVG
http://free.avg.com/ww-en/download-avg-anti-virus-freeAvast
http://www.avast.com/free-antivirus-downloadIf u find out that these antivirus work perfectly and u shutdown with no problems then its time to call the Bull Guard and ask them either to solve ur problem or maybe a refund