My windows used to minimize to taskbar & appear side by side now they are near to notification area grouped on top of each other with arrow beside to switch between them .How do I get them back as before ?
it's close to what I meant, you had probably increased the size of your quick launch so it was not leaving enough space, turning it off and on again reset the size.
Now right click anywhere on your taskbar and select lock the task bar to stop it happening again.