It is not possible to have multiple LogMeIn installations on a computer. A computer can only be attached to one LogMeIn account at a time. Also, there can only be one remote session at a time. Two or more people cannot remotely control a computer simultaneously. In order for someone to gain access to the computer(s) in your account, they would have to login to your account using your account email and password. They would then have to enter the computer's credentials in order to gain access. It is possible to add users or invite someone to remotely control specific computers in your account. This ability, however, requires an active subscription to LogMeIn Central.