Here are some essential Windows shortcuts that can really help boost your productivity:
General Shortcuts:

Ctrl + C: Copy the selected item(s).
Ctrl + X: Cut the selected item(s).
Ctrl + V: Paste the copied or cut item(s).
Ctrl + Z: Undo an action.
Ctrl + Y: Redo an action.
Ctrl + A: Select all items in the current window.
Alt + Tab: Switch between open apps.
Ctrl + Shift + Esc: Open Task Manager directly.
Ctrl + D: Delete selected item(s) to the Recycle Bin.
Shift + Delete: Permanently delete selected item(s) without going to the Recycle Bin.

Window Management:

Windows Key + D: Show or hide the desktop.
Windows Key + E: Open File Explorer.
Windows Key + L: Lock your PC.
Windows Key + M: Minimize all windows.
Windows Key + Tab: Open Task View for managing desktops and tasks.
Alt + F4: Close the current window or app.
Windows Key + Arrow Left/Right: Snap the active window to the left or right side of the screen.
Windows Key + Up/Down Arrow: Maximize or minimize the current window.

Virtual Desktops:

Windows Key + Ctrl + D: Create a new virtual desktop.
Windows Key + Ctrl + Left/Right Arrow: Switch between virtual desktops.
Windows Key + Ctrl + F4: Close the current virtual desktop.

Browser Shortcuts (works in most browsers):

Ctrl + T: Open a new tab.
Ctrl + W: Close the current tab.
Ctrl + Shift + T: Reopen the last closed tab.
Ctrl + Tab: Switch to the next tab.
Ctrl + L: Focus on the address bar.

Accessibility:

Windows Key + + (plus): Open the Magnifier to zoom in.
Windows Key + ESC: Exit Magnifier.
Windows Key + U: Open Ease of Access Center.

Search and Navigation:

Windows Key + S: Open Windows Search.
Windows Key + R: Open the Run dialog.
Windows Key + P: Open the projection options (to connect to a display).

File Management:

Ctrl + N: Open a new window (in File Explorer).
F2: Rename the selected item.
F5: Refresh the current window.

Screenshot Shortcuts:

Windows Key + Print Screen: Take a screenshot of the entire screen and save it.
Windows Key + Shift + S: Open Snipping Tool to capture a portion of the screen.
Alt + Print Screen: Take a screenshot of the active window.

These shortcuts cover a lot of different aspects of using Windows, and mastering them can really help speed up your work!