Ok so I may have finally found the best solution for anyone who like myself was looking get to S4/S4 TSS again and no longer has the CD copy.
Here's the link I found to a steam thread that explains it, supposedly it's legal to sell it for free since S4 is now classified as freeware according to the user. Hope it works for you if you need it.
https://steamcommunity.com/groups/Swat4Steam/discussions/0/152390648097675112/
*UPDATE - This download worked perfectly for me, was able to get S4 TSS running perfectly last night in under an hour.
Great, thanks for the tip!
SAS_LtCol_DeCapi
Commanding Officer
GCHQ
22nd [SAS] Elite Virtual Regiment
oh i have the cd copy but i lost the key . that sounds great to have a couple of rounds in swat ...yeah:)
Had a few rounds with Ranger the other day. Lots of fun.
SAS_Vet_Random
Lt. Col (Retired)
22nd [SAS] Elite Virtual Regiment