Thinking back it was probably default from 98SE onwards, I think before that it came as part of the IE4 bundle that was well known for trashing systems with the lovely "Active Desktop".
I remember it being awesome, one time I had a job to collate daily sales figures going back years stored in Excel documents (one per day, all in random folders under "c:\accounts") lol. So I could either open up ~900 xls and find the numbers as was the plan, or... WSH wscript.exe to the rescue! did it in about 20 minutes (not counting the day it took me to learn / write the program). And I could be sure all the generated weekly/monthly/yearly totals were all accurate too easily scanning the generated big sheet
that was a satisfying job imo!