500 error on web stats internally

[TRACEYR]

I keep getting 500 error internally i.e one client accessing the web server through network, only internal clients are getting this anyone outside of the network does not get this error

What can i do to trap this or figure out what is causing this.

[pageoneresults]

What we've done is contact the user and had them replicate what they did to initiate the 500 error. We then ask them to go to Tools > Internet Options > Advanced > Show friendly HTTP error Messages (in Internet Explorer). We will then ask them to read to us what they see on their screen.

[TRACEYR]

I think its my own machine lol.....thats a good idea i try that

[TRACEYR]

I have that set, but no message gets displayed to my screen, it is just being recorded in the log stats, with - (for the page accessing).

Where should i go now..any ideas.