PuTTY’s copy and paste works entirely with the mouse. In order to copy text to the clipboard, you just click the left mouse button in the terminal window, and drag to select text. When you let go of the button, the text is automatically copied to the clipboard. You do not need to press Ctrl-C or Ctrl-Ins; in fact, if you do press Ctrl-C, PuTTY will send a Ctrl-C character down your session to the server where it will probably cause a process to be interrupted.
You might try adding a Shift to your commands, so Ctrl+Shift+C / V. That is how copy pasting is done in the terminal (Ctrl+C is used to abort terminal commands). Alternatively you can try pasting by pressing Enter or the middle mouse button.
Also you don’t need Putty in Ubuntu: you can simply ssh using a terminal. For example if you want to connect to test.server.com, you simply type