The single best action you can take to increase the operating speed of your computer is to increase the RAM.
In the dental office speed issues are often not related to the individual machine you are using but to the network and the server.
If you have a server also acting as a work station (a peer to peer network) do not use that peer server for everyday computing. For example the server is often the front desk computer. If it is being heavily used as a work station it will slow down everything else in the office.