I heard that, for viruses such as Keyloggers, they store information in application data before retrieval, and that in order to find out if you do have a keylogger, in cmd you can execute these commands:
cd %appdata%
*enter*
dir /A-D /B
*enter*
And that you can find out if you have a keylogger here.
I'm not entirely sure, but hey.
If there is any other ways (without assistance from a program) that you can find viruses, please say!
Thanks.