Hello,
The best source for minimum system requirements of NI software is to check the release notes for that product. For LabVIEW 7.0, both the minimum system requirements and the recommended specifications are outlined at:
LabVIEW Release Notes - April 2003
For NI Vision 6.0, I would suggest looking at:
IMAQ Vision for LabVIEW Release Notes - October 2000
Looking at this documentation, running Windows 98 with a P3 or better processor with at least 180 MB of free disk space and 128 MB of RAM should work. However, as with most specifications, the faster the processor and the greater the amount of RAM and disk space that you can provide, the better your performance will be.
Please look at that documentation and let me know if you have any additional questions.
Regards,
Scott R.
Applications Engineer
National Instruments
Scott Romine
Course Development Engineer
National Instruments