Keyboard shortcuts allow you to perform different Windows actions quickly and improve your productivity. Here is a list of several effective keyboard shortcuts with Ctrl button and with Windows key. Give them a try and you may change forever the way you perform some actions in Windows. Here is the list:

Ctrl shortcuts

Ctrl+Shift+N:  Create a new folder;
Ctrl+Shift+Esc:  Open Task Manager; 
Ctrl+A: Select all items in a document or window;
Ctrl+Right Arrow:  Move the cursor to the beginning of the next word; 
Ctrl+Left Arrow:  Move the cursor to the start of the previous word; 
Ctrl+N:  Open a new window; 
Ctrl+W:  Close a window; 
Ctrl+Esc:  Open the Start menu; 
Ctrl+P:  Print a document; 
Ctrl + Shift + T:  Resume closed tab; 
Ctrl + Tab:  Move forward through different tabs; 
Ctrl + Shift + Tab: Move back through tabs. 

Windows key shortcuts

Windows key +S: Open search bar;
Windows key + E: Quickly access your Hard Drives; 
Windows key + X: Open the Quick Link menu; 
Windows key + R: Open the Run dialog box; 
Windows key + D: Display and hide the desktop; 
Windows key + Ctrl + F: Search for PCs in a computer network; 
Windows key +Down Arrow: Minimize current desktop window; 
Windows key + Up Arrow:  Maximize the window;
Windows key + T: Cycle through apps on the taskbar;
Windows key + Spacebar: Switch input language;
Windows key + L: Lock your PC or switch accounts.

Share some of your favorite keyboard shortcuts.

My favourite ones are:

Ctrl+Alt+Del (or a.k.a. the "three-finger salute":  It used to be the combination to invoke the Task Manager in earlier Windows versions, now it brings up a menu from where you can start the task manager, kill applications or perform an action like sleep, restart or shut down the machine;

Alt+F4: Kill an application or close the currently open window.

Alt+Enter: switch a window to full-screen and vice versa.

Its funny that I recently discovered the Windows Key + X shortcut and now I'm addicted to it.

Nice tips :3
I didn't know some combinations

Nice tips :3
I didn't know some combinations

Yeah, it's useful. Especially after you learn them and begin using them to save time.
If you know some combos as well - you can also share them. Or if you know some PC tricks.