Now Windows especially Windows 8.1 are running on many tablets. Windows tablet are almost as powerful as a laptop, and as handy as a mobile device. There are usually a SIM card slot on Windows tablet so we can use cellular network to access internet everywhere anytime. But not only use the internet or mobile broadband, it also capable to send and write SMS and USSD dialing.
Although maybe you do not find any app or program to send and write SMS preinstalled on your Windows tablet, but we can do it by using a windows app or software called 'Mobile Broadband SMS Toolkit'.
Mobile Broadband SMS Toolkit is a Windows app or program that allow us to send and receive (read) SMS message. It also capable to do a USSD dial, but not voice call dial. USSD dial is where we dial the operator menu, e.g. '*123#'.
But as I using it until now, the USSD dial seems only work for final path of the operator USSD menu. It won't work and will give me error message if I just dial the root of USSD operator menu e.g. '*123#'. The USSD dial only work on specific menu (the final path of USSD menu), for example '*123*7*3*1#', it is a dial menu to check my internet data quota on my SIM card operator. I don't know if this is a country-related only broadband service issue (I live in Indonesia), maybe?
Mobile Broadband SMS Toolkit is running well on my Advan Vanbook W80 Windows 8.1 tablet. The program is portable, so we only need to double click the launcher (application / exe) file to run it. And don't forget to turn on the 'Mobile broadband' option in 'Network' setting first, because without that this app will be useless :D.
Mobile Broadband SMS Toolkit Windows software download link
-> Download the latest version of Mobile Broadband SMS Toolkit Windows app on the official site.