When you say photoshop cs, do you mean photoshop cs aka photoshop 8 circa 2003/2004?
It just says CS but I have had it for years (around 2003).
It would work except that adobe shut down the activation servers for photoshop cs/cs2, so you wouldn't be able to activate photoshop cs once you got it installed.
You can download the non activation version of photoshop cs2 as a replacement and use the serial number provided on the same page.
You might find that photoshop cs2 doesn't run that great on windows 8.1, so you could try it or consider getting photoshop cs6 (perceptual license like you have now) or cc 2014 (subscription)
both of which work much better on windows 8.1
Thank you for the info.