PWSTray.exe
(Microsoft)
The Microsofts Personal Web Server which, when it runs, sits in the System Tray. The Microsoft Personal Web Server is used primarily by the Microsoft web publishing programs, FrontPage and FrontPage Express, to enable you to view locally on your PC , the web pages that you have designed. You can right-click on the icon in the System Tray to stop the Personal Web Server (PWS), to pause it, restart it, or to modify some of the options. Also, hovering the mouse pointer over the icon tells you whether PWS is stopped, running, or paused.
Recommendation :
If you have PWS running, the likelihood is that you have either FrontPage or FrontPage Express on your PC. If you use either of those, you will need the Microsoft Personal Web Server running so you can view your web page designs before uploading them to your LIVE website.