You are not providing nearly enough information for anyone to begin guessing. Consider a full outline of what you are doing, how you are doing it and what you are doing it with.
In order to help you, please include the following information in your reply....
What version of Premiere Elements, and what Windows operating system is involved?
Do you have the latest version of QuickTime installed on your computer along with Premiere Elements?
If you download and install the VLC Player, do you then have video as well as audio playback in the playback of your export? What players are you using now?
Is your video card/graphics card driver version up to date according to the web site of the manufacturer of the card?
Exported video to my PC desktop and playback is only the audio.
Please indicate whether or not you have audio within the edit area of your program, that is, is the audio lost only in the export file?
If this is the case, then I ask "What are you exact export settings?" If you repeat the project in a new project, do you have the same export problem with the same video format?
Depending on your answers to the above, the following questions will need answers also...
1. What are the properties of your source media?
2. What is your project preset according to Edit Menu/Project Settings/General?
3. Do you have the latest version of QuickTime installed on your computer along with Premiere Elements?
Please consider, and supply more details. If any questions or need clarification on the above, please do not hesitate to ask. We can go at whatever troubleshooting pace you prefer - and step by step if needed. Your answers to the specific questions that I have asked will expedite matters.