I live in a motel which offers free WiFi. I live on the top floor where I barely get a signal. How do I strengthen the WiFi signal on my HP desktop?
There's very little you can do by yourself, other than get replace your aerial or get a USB WiFi adapter, put it on a long USB cable and move it around the room in search or better reception. Either of these may make a different, but it is likely to be slight.
What you could do is talk to the motel ownwers. They can install a WiFi extender (a.k.a repeater) somewhere between the router and your room, improving the reception, or better yet, they may be willing to install a Powerline setup (see http://en.wikipedia.org/wiki/Power-line_communication for an explanation). In fact, you can suggest that they install a Powerline adapter next to the router and you will buy your own for your computer. I have made similar suggestions to the owners of a small hotel (after I left - I only stayed there a couple of days) and they took up the suggestion and wrote back to me to thank me for improving their service!
maybe you need range extender ask your motel support if possible