The taskbar is a horizontal bar at the bottom of your desktop in Windows 11 that shows the Start menu, Search, Task View, Widgets, Chat, File Explorer, Microsoft Edge, and Microsoft Store icons aligned to the center by default. The taskbar corner includes the notification area icons, Quick Settings (Win+A), and Notification Center (Win+N) with the clock and calendar.
When you hover the pointer over an icon on the taskbar for an open window, it will show a thumbnail preview of the open window.
If you like, you can change the size of taskbar thumbnail previews to a smaller or larger size in pixels.
This tutorial will show you how to change the size of taskbar thumbnail previews for your account in Windows 10 and Windows 11.
EXAMPLE: Default and 300 pixel size for taskbar thumbnail previews
Open Registry Editor (regedit.exe).
Navigate to the key below in the left pane of Registry Editor. (see screenshot below)
Do step 4 (change) or step 5 (default) below for what you would like to do.
If you don't have a MaxThumbSizePx DWORD, then right click or press and hold on an empty area in the right pane of the Taskband key, click/tap on New and DWORD (32-bit) Value, type MaxThumbSizePx for the name, and press Enter.
If you don't have a MinThumbSizePx DWORD, then right click or press and hold on an empty area in the right pane of the Taskband key, click/tap on New and DWORD (32-bit) Value, type MinThumbSizePx for the name, and press Enter.
Close Registry Editor.
Either restart the explorer process, sign out and sign in, or restart the computer to apply.