If I am understanding what you are describing correctly, that sounds like a virus.
Also, it sounds like Photoshop is still working great, but it is the only program that is working great.
Are the icons on your desktop shortcuts? Or are they files? If they are files, it sounds like they have had their file association set to Photoshop. Which means when you double-click them, the OS will use Photoshop to open them. This is something that is set within the OS, not within Photoshop.