I recently bought a new computer with relatively average specs, and put an old hard drive in it. I had to activate Windows, fix a file corruption that prevented Windows from updating, manually installed a graphics card driver that was preventing the hardware from working, and I still have nothing over 20 fps, even in the campaign.
I have no idea what's causing this. I don't want to re-install the game because it's pretty much the entire reason I even put the old hard drive into it. I looked for prvious posts on the same issue, and even found this troubleshooting guide, but none of its suggestions seemed to help. I'm under the impression that something in this computer is not compatible, even though I know for a fact that everything is updated. I looked for signs of a faulty hard drive and I don't think it's that because I don't see any issues outside StarCraft. If anybody has suggestions, or if anyone knows who I might be able to take this issue to, please let me know.