First, make sure that the keyboard/mouse is connected properly to the PC.
If this is not the issue then contact a member of NUIT Cluster Room Support (CRS) staff. In the Philip Robinson Library and Marjorie Robinson Library Rooms there is a CRS Helpdesk (staffed hours vary per site). In the Walton and Law Libraries you should use the cluster telephone to call x85999 to report the issue and ask for assistance. You will need to state your Newcastle University Campus ID (e.g. B654321), your location and the PC identifier (the number on the PC).
Unfortunately, outside staffed hours you may have to wait until the next day for assistance.