1) Ctrl+Z: Undo
Whether you’ve deleted a file or a paragraph all you need to do is simply press Ctrl+Z to undo any action.
2) Win+PrtScn : Screenshot 
Save time and instantly screenshot your screen by pressing Win+PrtScn. This shortcut saves you time from having to use the snipping tool. 
3) Ctrl+A: Select all
This command allows you to select all the text in a document or select all files in a folder. 
4) Alt+Tab: Switch apps
We all have multiple applications open at once, but with this command, you can easily switch through all your tabs. 
5) Alt+F4: Close apps
It can be a pain to go through each and every tab to close. This shortcut saves you time by shutting down all your tabs at once. 
6) Win+L: Lock your computer
It’s important to always lock your screen as it stops people from prying into your personal work. By pressing Win+L you can instantly lock your screen and ensure that no one can access your desktop.
7) Win+S: Search Windows
The window taskbar has a useful search box that allows you to ask any questions to Cortana or quickly search for any files 
8) F5: Refresh
Sometimes a page takes a while to load, by pressing the F5 key you can refresh the page where it will show you the latest version of the page you are looking at. 
9) Ctrl + C: Copy 
Instantly copy text, file or image by pressing Ctrl + C
10) Ctrl + V: Paste 
After copying something with the command above for example some text. You can paste the text by pressing Ctrl + V