I use Windows 7 and I installed HanYu Pin Yin software provided in the choices by the computer. I don't know if Windows 8 works the same way as Windows 7. I also use New Bopomofo 新注音輸入法 software where I can switch it either in Chinese character format or ABC English format. i hope that will help you a little bit.

yes there are many alternatives.The most popular ones, from my top of head, are 'sogou' and 'baidu'. They are both very powerful input methods, and they are used by millions of ppl everyday. by the way, I haven't met anyone who use 'Microsoft pinyin' when I was in china.

Maybe you can try this site. http://www.pinyinput.com/?lang=en

小狼毫（Rime） https://code.google.com/p/rimeime/wiki/Downloads I use Windows 8.1 and I have used 小狼毫 to enter Traditional characters with pinyin since using Windows XP. It always works well.