Thanks for your reply Jacob,
I don't have any other options of internet connections except this broadband stick so I think I have the same problem as you are BUT****here is a situation we differ:
EVERYTHING on my Windows 8 laptop works with my broadband connection (the People app, the OneNote app, the Weather app and web browsers) EXCEPT the Windows Store. Yeah, everything, including Windows Update. This error exclusively happens to my Windows Store.
I wonder if I'm the only one having this problem but anyway, thanks.