Is there any way to copy text that's shown in the Command Prompt window
C:\Windows\system32\cmd.exe to the clipboard?
Right click on the title bar and go to edit menu
All the options you need are there (copy, paste, select)
or To change the option to allow quick editing
Right click on the title bar and go to properties > quickedit mode enable.
Now you don't need to go through the edit menu to select or copy or paste.
Enter short cut to copy
Right click short cut to paste
Left click drag to select text.
Every thing is put into a the system clip board so crtl + v will work in to other applications like notepad.
Enter marking mode: Alt+Space,E,K
(yes, these are just the hotkeys for the process described in nelaar's answer).
Move the cursor with the arrow keys to the start of your selection (the selection is rectangular).
Hold Shift to select text while using the arrow keys to expand your selection.
Press Enter to copy the selection to the clipboard.