Starcraft is free to play, and the CD keys won't provide with anything on modern Battle Net. Anything older than I think the 1.12 installer (on the Jim Raynor dog tag USB drive or the long discontinued Battle Chest, I think) isn't designed for modern OSes, so it may not install correctly. That being said, you can still use those CDs to install on an older system and patch it up to I think 1.17.

Tiberian Sun is freeware, though I don't know if it's still out there to download. I know Tiberian Dawn (not pictured, also known as C&C 95) had a limited release of the CD images.

As for the others I would imagine they may or may not run on 64-bit OSes if anything is not 32-bit. The biggest hurdle I've dealt with is graphical corruption because of how the APIs have changed over the years; I opt to still run those games on similar hardware for the era.