I am sorry to hear that you have had issues with Vsync feature.
I would need more information in regards to your system configuration:
Operating system version?
Is your operating system 32 bit or 64 bit?
Also, the exact processor model on your system:
Click the Windows icon, and then right-click Computer.
Find System Type on the Properties window, and then note the processor model.
Does this problem occur with drivers provided by the board or computer manufacturer?
Please make sure to list your games, and I will try to replicate this matter as soon as possible.