Hi, I am running Windows 10 Pro. I have noticed and established that every time there is high GPU usage (with no other apps running except Thunderbird) it is related to Thunderbird. I have established this by methodically testing the system over many months by omitting other apps that might be using high GPU. The Graphics adapter is a Quadro M2000 and the usage spikes to about 20% or 30% (sometimes more). The GPU usage spike happens quite regularly but does not happen continuously (it is intermittent). Once I close Thunderbird (and having already omitted other apps), the GPU usage immediately drops to zero and never spikes unless I open Thunderbird and had it running for a while. The task manager shows the GPU usage is related to Client Server Runtime Process but I am highly certain that the GPU usage is related to a running instance of Thunderbird (regardless of what it shows on the task manager). I have also asked Bitdefender (the antivirus company) to examine my system. They did not find any malicious software. They say if it is something related to Thunderbird, I have to take it up with the software developer directly. I have kept Windows 10 Pro updated and the problem remains the same. I have updated the Nvidia Quadro driver and the problem remains the same. I have disabled hardware acceleration in Thunderbird and the problem remains the same. I have set the graphics card to dedicate to graphic tasks and the problem remains the same. I have a Bitdefender protection running on my system and the problem remains the same. Please assist. Kanay Chellapa