Last week I bought a Chinese handwriting input pad, by UnisCom 紫光电子， to use in my old Windows XP laptop. Even though I already had the "Control Panel -> Regional and Language Options -> Languages -> Install files for East Asia languages" option checked, when launching the Chinese Handwriting software, it was still unable to display the Chinese characters properly in the software. I also installed the "谷歌拼音输入法2.0" but same problem.
Finally, I found a fix in Microsoft. It is called Microsoft AppLocale Utility.
According to Microsoft:
"AppLocale (or Application Locale) is a temporary solution to these limitations caused by non-Unicode applications running on the Unicode (UTF-16) based Windows XP. AppLocale detects the language of the legacy application and simulates a corresponding system locale for code-page to/from Unicode conversions."
(1) Download AppLocale from Microsoft http://www.microsoft.com/en-my/download/details.aspx?id=13209.
(2) Install AppLocale.
(3) Launch AppLocale and browse to the application you want AppLocale to simulate.
(4) Select desired language.
(4) Check "Create a shortcut to always run this application with AppLocale".
Now, launch the application from the AppLocale newly created shortcut and you will have a perfect Chinese characters.