Quartus won't run or uninstall

Hi all,

I've installed with Quartus II 15 Web version and ModelSim 10.3d onto my desktop for numerous courses I am having at my university.

I have been used Quartus for the past 3 weeks with no problem, but since yesterday, my Quartus won't run at all. I tried double clicking it and run as an admin, but Quartus just wouldn't start. when i checked the task manager after attempting to run quartus, no program associated with quartus was running.

I even tried to uninstall it using its uninstall exe file, but it has the same problem.

the funny part is that, my modelsim 10.3d can run swimmingly on my PC.

Has anyone experienced this issue or know how to resolve this problem?

Thanks,