After installing WIMS you may see the below error:

Run-time error '91'

Object variable or With block variable not set.

This indicates most likely the SQL native client was not installed.  Confirm in Add/Remove programs.

To install the SQL native client, you can launch the .msi from a Hach WIMS DVD (or extracted DVD)

After a successful installation you should be able launch WIMS with no error 91.