Chinese input, please help. I can't type chinese anymore

I used to use Microsoft Pinyin. I always have problems when I switch between Chinese and English. Most of time, I can't switch back to Chinese by pressing "shift" key. Now it totally stopped working.  I deleted the program, and tried to installed Google Pinyin input. However, the instruction is in Chinese that my computer doesn't recognize.

What is the best Chinese input software? Where can I find one with English instruction for installation?  Many thanks!