Only problem is that the date gets screwed up. Its a know problem and an upgrade will fix it. But I dont want to fork out 500 € just to fix this little problem (and I only use STEP5 occasonally anyhow).
Only the latest version of Step 5 will run on windows 98 or later, I think this is version 7. I keep a laptop with windows 95 on it to Run my version which is Step 5 V6.65.
The S5 PLC became a "mature product" in October 2003 so I am currently replacing them with S7 or Allen Bradley.
if you have a shortcut on the desktop, rightclick on it and choose Properties. Go to the memory tab and set everything to 'Auto'. This did the trick for me, even with Step5 V3.0 on W2K.