Other than the fact I don't let it install to Program Files (which, to be fair, I don't do with -any- of my games), no idea.
I have to do it on my desktop too. Actually... I just had a thought. I wonder if it's because I launch the game directly from TS3W.exe, because that's the file I always patch.
After all, there's 5 executables in the base game DIR (S3Launcher, Sims3Launcher, Sims3LauncherW, TS3 and TS3W)
Also, if you think about it, most people in June 2009 were running systems with 2-4GB RAM and Windows XP... -maybe- Vista, and even then it wasn't guaranteed to be the 64-bit version.
It's highly likely EA didn't make the game LAA compatible to ensure it ran on these older systems. At that point, I was running XP Pro 64-Bit edition and had 8GB RAM in my machine... so I was an oddity.