I have a Lenovo ThinkPad T500 and 95% of the time I use the laptop connected to an external flatscreen, a keyboard, and a mouse. Is it possible to close the laptop screen/lid without putting the laptop into standby, i.e. keep the laptop running with the screen closed?
If you use Lenovo's power manager, open it by clicking the battery icon, and in basic mode you can see on the left side 'change what closing the lid does and enable InstantResume to stay on-line' click in here and choose "does nothing / no action"
In advanced mode, under your current power plan, expand Events with the arrow on the left and choose do nothing for lid closed.
Older versions of power manager had this setting listed under Global Power Settings Tab.
If you don't use power manager go in the windows control panel ->hardware and sound ->power options. You can see on the left Choose what closing the lid does. Go there and select do nothing for when I close the lid.