Can't Download the game on my Second Pc

Could you please post your dxdiag?

Try right-clicking the Steam icon in the system tray and selecting Library. Then right-click Oxygen Not Included and select Properties. Select the tab labeled "local files", and click the button labeled "verify integrity of game files". On the Local Files tab, make sure that just above the buttons it says Disk Usage: 890 MB on drive (whatever drive you have it installed on). It almost sounds to me like the game files aren't even installed on the computer.