Over the past few weeks one of our PCs started to slow down unexpectedly and utilized high CPU resources while we accessed the Internet. We were quite perplexed as every time we downloaded emails in Outlook, or downloaded files from the Internet the CPU usage would shoot up to 100%

Turned out the problem was due to AVG network scanner, which was making use of DPCs (Deferred Procedure Call ^[1]) to create high-priority tasks to scan the network, which in turn slowed down the PC by shooting up the CPU resources.

At times you may also see problems while accessing regular websites, where pages may not load and show connection timeouts.

The next time you are facing a slowdown while using the Internet, you can open task manager to see which process is using the most CPU resources, if you see DPCs taking up most of the resources, you can disable the AVG Network Scanner and then try see if the problem is solved. This may also occur with other Anti-virus software, disabling the Network scanner will fix the issue.

If you have any questions related to PC problems or problem with a application, feel free to ask us ^[2], we will try our best to find a solution for the problem.