Windows 7: Safely remove OS disk - what would happen?

Since I have jumpy hands with a disability it is scaring the pants off me to find that Windows 7 allows me to pick my internal drive from which I am running the OS from the list of drives to stop with "safely remove hardware". It does seem like the world's stupidest question, and surely I will just get that "something is using this drive I can't stop it now" error, but will it do anything horrible if I accidentally hit that button one day? If it could all go horribly wrong, can I do anything to permanently hide the OS disk from the remove hardware options?

Thanks.

You have nothing to worry about. Windows won't stop or disconnect a drive that has any programs running from it (including windows itself)