Hugh (and others),
The hidwatch.dll file was required by earlier versions of Express Scribe, but is no longer needed with v 4.xx releases of the software.
If you are being asked to install this file then you have two choices. Either send an email to technical support (nch@nch.com.au) asking for a copy of this file, which we will send as an attachment by return email, or download and install the current version of Express Scribe.
nchpm