How do I disable rtvscan as it is slowing down pc's to a crawl ?

You can turn off the realtime scan in the options area of Symantec.

Another solution would be to uninstall symantec altogether... I prefer AVG antivirus myself... the personal version is free.

AVG is a good anti-virus software. AVG just came out with the 8.0 version that includes anti-spyware. Their site is AVG Free - Download antivirus and antispyware software for Windows XP and VistaAnother one is Avast that also has a free version.