First Microsoft Office is a great Program, but if you just use Word you could try Jarte (freeware)
(word processor uses Microsoft's reliable, fast starting WordPad word processing engine while adding many features missing in WordPad)
its light and works well.
PCs tend to slow with more apps installed, rubbish build up, corruption etc and if you don't want to install even more apps to clean try >
1 Click your start button on your desktop (bottom left)
2 In search type cmd , this will bring up your jump list and you will see the black cmd Icon right click on it and in the drop down menu click (run as administrator)
3 In the black cmd (command prompt) window type cleanmgr/sagerun:1
and press Enter/Return on your Keyboard, the cleaning process will run.
4 After the process has run (a matter of seconds) in the cmd window type exit and press Enter/Return, the cmd window will close and your system has been cleaned.