The next thing to consider is whether you have malicious software on board your systems.  Mal ware can choke your desktops, take over your websites or otherwise plant information in your desktops and servers that could steal precious and private information. As these programs are running in the background the obvious is that your machine is running  very slow.  We have a client recently complaining of the same thing and found that a worm was introduced into his workstations and server.  The had the ability to download other software into his system.  In addition we found other software that was able to take over his website if that information was on either of his machines.  For more see http://www.helpsolveit.com  then click on the article about spyware.  More to follow..