I usually do slides directly in PowerPoint, or just fix the formatting after copying and pasting.

However, if you don't want to do that, you can open the word document and hit the print screen button on your keyboard (it's usually in the upper right corner). This will copy everything on the screen to the clipboard. You can then use the paste command in PowerPoint, and crop it so only the text is showing. You can also resize it to fill the slide. The resolution might be slightly degraded doing it this way, but will be good enough for most purposes.