Unable to Start Game error

Hey, so I've installed the Sims 3 and it's expansions (+ a few stuff packs) in my G:games folder, following the installation guide as best as I could. After I installed it I couldn't run the game from the TS3W.exe getting the seemingly notorious "Unable to start game service initialization failed 0x0175dcbb" error. While I was trying to figure it out I noticed that the update to the latest version had installed another Game and Gamedata folder inside the folder where I put the separate folders for the Sims 3 and it's expansion packs (I checked this by removing those two seemingly wrongly installed folders and running the update again; which caused the folders to reappear).

Thinking this might be causing the issue, since it seemed the game might not have been updated properly, I dragged the two new Game and Gamedata folders to the Sims 3 folder and replaced it's contents. Following that, I ran the TS3W.exe in the new folder. Now I get an "Unable to start game - your the Sims 3 Base Game is incompatible with the current Sims 3 Expansion pack. Please update your game via the game launcher" error. At this point I've basically muddied the waters so badly I can't even tell what I did wrong exactly (but probably everything), so please help. I've been trying to get this game working so long I've already fallen asleep at my pc once..

Alright so I've run the manual patch and now another Game and Gamedata folder have appeared outside of the Electronic Arts folder I installed all the games in. I've tried using the TS3W.exe files to start up the game and I get my initial error again (the "service initialization has failed: 0x175dcbb" one). Looking through previous topics that seems to be a registry thing, so I started up regedit and looked at the Electronic Arts files, and I can see two folders in there: one saying EA Core-> Installed Games-> sims3-dd / sims3-ep01 / sims3-ep02 etc, the other one simply saying: Sims-> Sims 3 / Sims 3 Ambitions etc. Based on the things I've read I don't think the EA Core folder is supposed to be there? Can I just delete that folder, or should I do something else?

No, my G: drive is an internal Hard Drive with 931 GB and I install pretty much all my games on it, except on rare occassions. Sadly I don't have any more space on my C: drive, otherwise I would've installed the Sims 3 there just to simplify the whole process.. So if I reinstall them all, what should I be doing to prevent this from happening again? Like I said, I can't really install it on my C: drive given the size of the Sims 3, so I'm stuck trying to get it to work on my G: drive.