Assume that you want to login your Gmail account on your friend's laptop and you are doubt if he installed a keylogger on his computer. How you can be sure if there is any key logger installed or not?
I guess it would require too much effort and still you would not be 100% sure.
- Have a reliable anti malware with the latest update perform a deep scan to look for it.
- If you are very well experience with the OS' processes, take a look to see if any unknown process is currently running.
- Check the connected USB devices to the computer. Two keyboards are a indication
What could help you:
- Use a system virtual keyboard to type in your password.