A virtual keyboard makes no real difference a sandbox might though if you can separate the viruses and key loggers from the main system, unless its already built into the software then its Microsoft 
This is another option you may try to use a sandbox and by doing that you can avoid most of the viruses on the internet, in fact you should follow that practice every time you install something new in your computer to avoid being infected by viruses.here is an easy idea: how about instead of bothering that much with Windows and all the headaches of malwares and key loggers, etc move onto linux at least for security stuff such as holding your bitcoins and other important matters.
Virtual keyboards can save you, but it will cause a lot of inconvenience to your work, assuming, if you use the key, you can finish the job in a short time, but if You use the virtual key, you have to perform all operations with the mouse, very inconvenient, and you will spend more money. A very cheap keyboard, you do not need to save on such expenses. Saving is good, but you need to save on time.
