I tried re-installing using a different internet connection (this time, a Cable Internet connection), and I was able to install everything without fail.
I normally use a HSPA+ broadband connection to install Windows Store Apps. Previously it is working, but for some reason it always fails now. There are times when I could install an app, but that's a 50/50 chance.
It's bothering me, because when I do a speed test, I still get a 1Mbps/2Mbps speeds, sometimes even 4Mbps, but I am still unable to download.
The same happens when I do Windows Update. The same error 8020002e code. But when I connected to a Cable internet connection (which is only 1Mbps), I could finish the installation.,