I assume the one that freezes is also a laptop not that it should make a
difference.
If you are trying to drag and drop or backup directly to CD, this is not
supported by XP's built-in CD burning ability. For that you need to have
packet writing software installed such as the Direct CD or Drag and Drop to
Disk component of Easy CD Creator,
www.roxio.com or the InCD component of
Nero,
www.nero.com, please see web sites for versions compatible with XP and
drive compatibility.
It's possible one machine has packet writing software installed while the
other doesn't and this might cause the system to freeze.
If the above is not the issue, are you able to drag any files to CD, please
describe the procedure you are using to backup and if you are using a backup
application, please give the name and version. If you are using such an
application, are you sure it is compatible with XP/
Something else to check is the Event Viewer. Open Control Panel, open
Administrative Tools, open Event Viewer, look for any errors that correspond
to then the problem occurred, double click the error, the information
contained within may give a clue as to the source of the error.
