Vim select buffer to the clipboard via a PuTTY SSH connection

I connect to my server via SSH. How could I copy lines from visual mode straight to the clipboard?

You can select the register in witch you can copy anything. The list of available registers is available through :registers. The clipboard register is usually "*. Therefore if you want to copy anything in this register, just prefix the yank command by the register, i.e., "*y. The steps would be like:

• Enter visual mode (Shift + V for instance)
• Select your lines (movement)
• Type "*y

To make the copy work with PuTTY, you'll have to enable X-forwarding, vf Copy from PuTTY/Vim visual mode to Windows clipboard.