Hardrive Encryption and uninstallilation

My main concern is Would it be safe to encrypt the data on my Main Diskdrive. and if i did would it still work. or should something come up would i be able to uninstall it?Im not very tech Savvy so Im unsure on weather it would be a good idea to use it or not. i just recently cleared my computer of a virus and im taking what precautions i can to keep it from happening again