System Slow Down After Installing Latest Updates

I recently completed an automatic update of Bitdefender antivirus on my Windows 8 laptop. Since that install, the system has slowed dramatically. I am having particular issues attempting to use MS Word (Office 365). The program is horribly slow (I type faster than the software can display) and crashes or freezes frequently. I've also noticed significant slowing of Internet browsing on all sites, most commonly on sites I utilize daily. When I temporarily disable BD, the issues go away. I receive no error messages. The laptop has 8GB of RAM and CPU speed is 1.80 GHz. Ideas? Suggestions? Please!