Even if inspected, you can show the letter from Microsoft, it will be ok. I encountered this at Tanjung Pagar.
Our customs officer there seems to be more strict compared to the one at Causeway, if you by foot or bus. I brought around a new unopened PC + monitor there. They did ask what's inside, I just say PC and they'll let go. I do heard that PC stuff is exempted from tax, but I don't know for sure.

10% of the stuff worth is not that bad...