As per the description provided you get an error while installing a software provided by APC.
Try these steps and check:
I would suggest you to create a System Restore point before you perform the steps mentioned in Method 2:
Sometimes, a new program can make your computer behave unpredictably, and uninstalling the program does not help. Windows XP has a feature known as System Restore that can help. You can use System Restore to select a time when your computer is working as you want.
Visit this link and try the steps to create a system restore point:
How to set a system restore point in Windows XP
It may mean the Windows Power Service. Try:
1. Click on Start and Click Run.
2. Type Services.msc into the box and hit enter.
3. Scroll down until you find Power, right-click on it and select Properties.
4. From the drop down menu select Diasbled. OK and exit Services.
5. Now try installing the PowerChute software and check.
Hope this information helps. If you have further questions feel free to reply and we would be glad to assist.