Thanks for your reply Craig.
I didn't make it clear in my original request. The Net framework was installed on the Windows 98 machine. The similar application I referred to, that did work, was also written under the visual studio environment using C# except it didn't have any NI components.
Any further thoughts would be appreciated. In the mean time I'll re-visit the Microsoft site you suggested and perhaps experiment with the NI-VISA components.
Regards