A virtual graphics processing unit (vGPU) is a type of hardware or software that enables a VM to use the physical GPU resources of the host or server for graphics-intensive tasks. Upgrading the vGPU is most likely to solve the issue of VDI performance being slow since the images were upgraded from Windows 7 to Windows 10, as it can provide more graphics processing power and memory for the VMs. Upgrading the vGPU can also improve the user experience and productivity, as it can enhance the display quality and responsiveness of the VDI environment. Reference: CompTIA Cloud+ Certification Exam Objectives, page 11, section 1.6