1. Ctrl + C : Copy selected text or files.

2. Ctrl + X : Cut selected text or files.

3. Ctrl + V : Paste copied or cut text or files.

4. Ctrl + Z : Undo the last action.

5. Ctrl + Y : Redo the last undone action.

6. Ctrl + S : Save the current document or file.

7. Ctrl + P : Print the current document.

8. Ctrl + F : Open the find/search function.

9. Ctrl + A : Select all text or files.

10. Ctrl + N : Open a new document or window.

11. Ctrl + O : Open a file.

12. Ctrl + W : Close the current window or tab.

13. Ctrl + Tab : Switch between open tabs or documents.

14. Ctrl + Shift + T : Reopen the last closed tab.

15. Ctrl + Shift + Esc : Open Task Manager (Windows).

16. Alt + Tab : Switch between open applications.

17. Ctrl + Alt + Delete : Access various system options (Windows).

18. Ctrl + Shift + N : Create a new folder.

19. Ctrl + Shift + V : Paste without formatting.

20. Ctrl + Arrow keys : Navigate text by word.

21. Ctrl + Backspace : Delete previous word.

22. Ctrl + Shift + Arrow keys : Select text by word.

23. Ctrl + Home/End : Go to the beginning/end of a document.

24. Ctrl + D : Duplicate selected text or items.

25. Ctrl + 1/2/3 : Switch between open tabs (browser).

26. Ctrl + T : Open a new browser tab.

27. Ctrl + L : Highlight the address bar (browser).

28. Ctrl + Shift + N : Open a new incognito/private window (browser).

29. Ctrl + K : Insert a hyperlink (some text editors).

30. Ctrl + J : Open the Downloads window (browser).

31. Ctrl + + / - : Zoom in or out (browser or document).

32. Ctrl + 0 : Reset zoom to default (browser).

33. Ctrl + Shift + S : Save as (in many applications).

34. Ctrl + Shift + P : Open a new private window (browser).

35. Ctrl + Esc : Open the Start menu (Windows).

36. Ctrl + Alt + L : Lock the computer (Windows).

37. Windows Key + D : Show desktop (Windows).

38. Windows Key + E : Open File Explorer (Windows).

39. Windows Key + L : Lock the computer (Windows).

40. Windows Key + R : Open the Run dialog (Windows).

41. Alt + F4 : Close the currently active application or window.

42. Alt + Enter : Open properties of selected item (Windows).

43. Alt + F : Open the File menu in many applications.

44. Alt + E : Open the Edit menu in many applications.

45. F2 : Rename selected file or folder.

46. F5 : Refresh or reload (browser or file explorer).

47. F11 : Toggle full-screen mode (browser or application).

48. Shift + Delete : Delete a file permanently (bypassing the Recycle Bin).

49. Ctrl + Alt + S : Save as (in Adobe software).

50. Ctrl + Alt + Shift + S : Save for web (in Adobe software).