Hello,
If the screenshot shortcut is Ctrl+Shift+A, it is usually set by a third-party software, and you need to go to the settings of the software to modify it:
Find and open the screenshot software.
In the software's settings or options menu, look for "Shortcut Key Settings" or "Hotkey Settings".
Find the Ctrl+Shift+A setting and modify it to a different key combination you want.
4.If you don't need the screenshot feature of the software, you can also disable or uninstall the software directly.
I hope this information helps.
Best regards,
Jingjing Wu