I setup a remote collector for a certain location but but all of the computers show they are being scanned by the central server.

2 Spice ups

http://community.spiceworks.com/help/Remote_Collectors

take a look through have you missed a setting?

have you cancelled the scan range of the central install and made one on the remote collector

have you given the remote collector a different name than the central install

have you ‘authorised’ the remote site