You'll need your XP CD for this - though the data should be on your systems in cab files already.
Go to Control Panel then Add/Remove programmes, at the side of this pane are 4 seperate icons, the one you want is Add/Remove Windows Components. the item you require is the very top one - Accessories and Utilities, double click on it then on Accessories, look at the bottom of the list, you should see Wordpad, is the check box at the side ticked? If it isn't tick it then click OK then OK on the next screen, this will start your system re-loading Wordpad.
After all this has been finished and you have left Control Panel, try starting Wordpad again, it should be OK now.
Download Ewido from www.ewido.com/en, load it and update it if necessary. Log off the 'net and reboot to Safe Mode, and then run Ewido on a full scan deleting anything it finds.
Now reboot to normal mode, you should be OK and have a clean computer.
Also could you put your system specs on your profile, that way when you need help, all you need to do is say ''for system specs, see my profile'' and we all can see what you're doing.
If you want to, look on my profile for some ideas, as often - as in this case - we don't only need to know what the specs are, we also need to know what anti-virus and spyware/malware protection you use.
Any anti-virus programme and spyware/malware detection needs to be kept up-to-date at all times, and it wouldn't hurt to have a good firewall as well.
If you use any anti-virus and/or firewall, remember, you can only use one at once, and if you do use a firewall, make sure the Windows firewall is disabled. If you try to run two or three together, the various programmes will tend to conflict with each other.
I use WordPad regularly. Overnight it has refused to open. When I click the Icon or go through the Start procedure and click WordPad, there is an instantaneous flash, like the screen is coming up,and I'm back where I was. It is almost as if a Pop-Up is being blocked but, there is no indication of this in the Tool Bar Area. I started to go through a System Restore but, I'd rather see what the "Experts" suggest first.