What's BG:T? 
But yes, you should start the 2 games(BG1 & BG2) at least once, to install your BGT-weidu... this is to add in the game configuration file to each game, which in BG2's case is the baldur.ini... if memory serves, and the USB connection didn't get eaten by a heretic.
Now, of course if you extract the game from a .rar archive that already had that done before it was packaged into an archive file, then you don't need to do that of course... you just need to check that the the files directories direct the game into the correct .bif folders. As the folder structure is sure to have changed for C drive... cause updated Windows freakouts. And if you have used other drives in the past, that's no guarantee of anything when it comes to new and old machines.
Why use archive instead of pure copy ? Cause it's faster to extract that to copy the game data.
Edited by The Imp, 11 September 2019 - 09:51 AM.
Yep, Jarno Mikkola. my Mega Mod FAQ. Use of the BWS, and how to use it(scroll down that post a bit).
OK, desert dweller, welcome to the sanity, you are free to search for the limit, it's out there, we drew it in the sand. Ouh, actually it was still snow then.. but anyways.