I have never heard of this type of problem before. Usually, for a small amount of costumers, the internet connection slowdown occurs with BullGuard activated.
In order to check which exact BullGuard plugin causes the issue, here is what I recommend:
1. Double-click on the BullGuard icon in the System Tray and open the application.
2. Go to the Antivirus section > Protection tab and turn off the On-Access Protection.
3. Check if the problem starts.
4. Go to the Firewall section > Overview tab and disable this BullGuard engine.
5. Check if the problem starts.
6. Go to the SpamFilter section > Overview tab and disable this BullGuard engine, as well.
7. Check if the problem starts.
Please get back to us communicating the results and which exact BullGuard plugin causes the issue.