I have been fixing PC & laptops for a living since 1992, andI can tell you that while many programs can run on old versions of Windows, the fussing and frustration usually isn't worth the effort. My recommendation for Windows XP SP3 for a starting point is based on keeping your sanity, temper and hair all in reasonable order. I would rather expend my efforts and energy fixing my Stang than fighting a balky old version of Windows.
I don't disagree. You just made it sound like a requirement, which it is not.
BTW, I've done the same since 1982, also designed custom VMEbus systems for military & aerospace with PC's providing the user interface, so let's not start throwing credentials around.
Since the makers of the software say it's compatible with all, I will have to take their word for it.
Tweecer software was written in 1997. Not really optimized for Win7, pics look like Vista or Win7. In some instances, the BDE has problems with Vista & Windows 7 security & large hard drives. Probably works best on Win98 or Win2k. Install notes below are dated 3/10/2011.
http://www.tweecer.com/downloads.htm
http://www.tweecer.com/dl/InstallGuide.pdf
Data Acquisition from an EEC-IV does not require a lot of computing power. I designed, built & tested DAC systems 20 years ago that were more complex. Control loop timing on a car is 10's of milliseconds, not microseconds.
Right now, I rather fight with a computer than fight with my Stang. I may just be buying this Tweecer instead of throwing money at FMU's, etc. I think I need a new set of injectors & 19lb are more expensive than 30lb or even 24lb. My SC has the capability of 13lbs boost, even if I never use more than 5-6 on the street. Might need a wideband HEGO to go with it.
The OP seems to have all the hardware he needs. A new set of injectors is about $200, don't know what's available in Japan or at what price. For $200, it's not worth the trouble to have them cleaned unless by yourself as a "science experiment".