Upon having no Chinese Input in your computer system, You are to try this online tool.
另外還有其他的：
UTF-8
http://people.linux.org.tw/~pofeng/ov-webime/zhuyin-kb.html(注音)
http://www.pinyinput.com (拼音)
http://www.cangjieinput.com (倉頡)
http://www.simpleinput.com (速成)
http://www.cantoneseinput.com (廣東話)