What version of Windows do you have? Microsoft included an Input Method Editor (IME) in Windows 2000 and XP that is supposed to allow you to enter Chinese characters without a special keyboard. My earlier experiments with Japanese didn't work out, so I'm no expert on this, but see if any of this helps:
Instructions from Windows XP Pro help:
If your version of Windows does not have an IME, you can download one here:
<hr>To add another keyboard layout or Input Method Editor (IME)
- <LI>Open Regional and Language Options in Control Panel.
<LI>On the Languages tab, under Text services and input languages, click Details.
<LI>Under Installed services, click Add.
<LI>In the Input language list, click the language for the keyboard layout or Input Method Editor (IME) you want to add.
<LI>Select the Keyboard layout/IME check box, if multiple options are available, and then click a service in the list.
If Keyboard Layout/IME is the only type of text service available, click an option in that list.
<UL><LI>To open Regional and Language Options, click Start, point to Settings, click Control Panel, and then double-click Regional and Language Options.
<LI>There may be only one keyboard layout for some languages.
<LI>To add an IME, you must have installed it on your computer first.[/list]<hr>
Office XP Tool: Global IME (Simplified Chinese)
Office XP Tool: Global IME (Traditional Chinese)
And these "language packs" might be the patch you already downloaded:
Office XP Tool: Simplified Chinese Language Pack
Office XP Tool: Traditional Chinese Language Pack
Even then, I don' t know if it will really ever be convenient to use; I think these are accommodation for occasional Chinese language input, and not heavy duty word processing.