Find My iPhone on Windows computer, Mac computer, or iOS devices is possible.
For your information, Find My Phone is a free app and also free amazing service provided by Apple to help you locate your stolen/missing iPhone4, iPhone4S, iPhone3GS, iPad or iPod Touch as well. People misplace things all the time. Fortunately, if you lose your iPhone, you can use Find My iPhone to help you finding a lost iPhone.
First thing you have to do is activate and setup Find My iPhone service on your iPhone/iPad/iPodTouch (follow this guide: How-to Use Find My iPhone) and once you have done that, you can find a stolen iPhone from any Windows computer, Mac computer, or even from an iPad / iPhone with Find My iPhone app installed with Internet data service enabled.
As long as your Windows computer has an Internet access and your lost iPhone has an Internet access enabled, you don’t need to worry about losing your iPhone.
Find My iPhone login portal is www.icloud.com which can be accessed from Windows computer using Internet Explorer, Mozilla Firefox, or Google Chrome browser.
Login to www.icloud.com by using Apple ID you used on the lost iPhone/iPad.