Windows 7: adminstrator or standard?

Standard user (Users) - A limited unelevated standard "users" account that can use most software and change system settings that do not affect other users. If a standard user wants to do an action that requires elevated rights or affects other users, then they will be prompted by UAC (if set to notify) to provide an administrator's password before being allowed to do so. If UAC is not set to notify, then the standard user will just be denied and not allowed to do the action.

Administrator - An unelevated administrator account that has complete access to the computer and can make any desired changes. Based on your UAC notification settings, administrators may be prompted to provide their password or confirmation before being allowed to open or run anything that requires elevated rights to do so, and make changes that affect the system or other users.