I had the same problem few years ago
I have just forgot to put my key
into the main TE menu
I say that, perhaps it's not the problem you have.
Is your new computer have a different graphic card? Perhaps you must config it with minimal graphisms, and change configuration after you have install mods
It look like a install problem, not a configuration one!
I try, as you, to understand the problem. Sorry if i don't have solutions...