You could install Google Pinyin (recommended) or go to Control Panel > Clock, Language, and Region > Region and Language > Keyboards > Change Keyboards and select the Microsoft Simplified Pinyin (PRC) system.
The Google Pinyin is much better, but the microsoft one will work, too! Windows only offers simplified pinyin (traditional needs zhuyin) and its prediction system is not very good, so you will have to proofread a lot.