why can't i purchase songs from the Itunes store using my PC, but I can from my Ipad?

I have a new Dell PC running Windows 8.1. I have downloaded ITunes and authorized both it and my Ipad. The problem is that I do not get the "Buy" option on my PC when selecting a song, however my Ipad works perfectly for buying music. I checked and rechecked my account settings and still cannot get my PC to allow me to make a purchase. Any advice would be greatly appreciated.

Thanks.