I agree with @bigtwin. If you are going to be living there for a while, then leave the system set up so you can listen. Mostly potential buyers want to be able to visualize what they would do with the various rooms in a house. Your system does not clutter up the room and should not have a negative impact.
If you are concerned from a security aspect with pictures of your system being posted in the listing, then buy some dark sheets and cover the speakers and components when the pictures are taken. Open houses are another consideration. Unplug your system, put the speaker grill covers on and, if you don't have speaker covers then, maybe buy a couple of heavy duty winter AC unit covers to put over the speakers. You don't want somebody or their kid poking their finger through your drivers.