I am a fairly new self taought AutoCad technician and i'm having problems with the current drawing that i'm working on.  It has a number of xrefs that I need to change and they are all in seperate files.  I can change them in the xref but when i go back to the master drawing they haven't changed? Help!!

Hello, first when you open your file, press the F2 button on your keyboard and read the errors messages about the good or no good Xref load.
launch the command XREF and read the state of the different Xref of the file.
The place where you have loaded the file on your computer and complete path of it is important.
Eventually, create the same path on your computer ( possible or not ).
Then you can also "play" with the xref manager :
On your computer : Start, Program, Autodesk, AutoCAD 2012, Reference manager.
See also :
http://www.cad-addict.com/2009/03/autocad-multiple-xref-repath-reference.html 
 philippe JOSEPH2012-11-08 11:23:06

type xrefxref box will appearclick on xref you have changed and  click on right RELOADshould work

Thankyou Very much - you have restored my sanity and so simple, as i thought it would be!!

If you are using AutoCAD 2012 there should be a notification bubble in the lower right corner of the screen anytime an xref file has been changed.  If this is not happening for you your XREFNOTIFY system variable may have been reset.  You want it = 2.0    Disables xref notification.1    Enables xref notification. Notifies you that xrefs are attached to the current drawing by displaying the xref icon in the lower-right corner of the application window (the notification area of the status bar tray). When you open a drawing, alerts you to missing xrefs by displaying the xref icon with a yellow alert symbol (!).2    Enables xref notification and balloon messages. Displays the xref icon as in 1 above. Also displays balloon messages in the same area when xrefs are modified. The number of minutes between checking for modified xrefs is controlled by the system registry variable XNOTIFYTIME.Dave.