how to disable word prediction in Windows XP.

sorry, what do you meen by word prediction?

do you mean in microsoft word?

If you mean auto complete:

Turning off AutoComplete completely
If you don't like seeing your user names, passwords, and other information sitting in drop-down windows, tell Windows to stop by doing this:

1. Open Internet Explorer.
2. Choose Internet Options from the Tools menu.
3. Click the Content tab.
4. Click the AutoComplete button.
5. Click to remove checkmarks from these items:

* Web addresses
* Forms
* User names and passwords on forms
* Prompt me to save passwords

6. Click the Clear Forms button.
7. Click the Clear Passwords button.
8. Click OK.

Deleting old entries from the Search Companion
But you're not through yet. Windows XP's Search Companion also includes an AutoComplete feature, so it can remember every file and phrase you've searched for. Here's how to turn it off, as well:

1. Choose Search from the Start menu.
2. Choose Change Preferences.
3. Choose Turn AutoComplete off.