判断电脑的系统，以及windows是否是XP

//判断浏览器
export const inBrowser = typeof window !== 'undefined'
export const inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform
export const weexPlatform = inWeex && WXEnvironment.platform.toLowerCase()
export const UA = inBrowser && window.navigator.userAgent.toLowerCase()
export const isIE = UA && /msie|trident/.test(UA)
export const isIE9 = UA && UA.indexOf('msie 9.0') > 0
export const isEdge = UA && UA.indexOf('edge/') > 0 
export const isAndroid = (UA && UA.indexOf('android') > 0) || (weexPlatform === 'android')
export const isIOS = (UA && /iphone|ipad|ipod|ios/.test(UA)) || (weexPlatform === 'ios')
export const isChrome = UA && /chrome/d+/.test(UA) && !isEdge
export const isPhantomJS = UA && /phantomjs/.test(UA)
export const isFF = UA && UA.match(/firefox/(d+)/)

   
//判断windows的系统
var version = navigator.userAgent;    
       if (version.indexOf("Windows NT 5.0")!=-1 ) {
         alert("windows 2000");
       } else if (version.indexOf("Windows NT 5.1")!=-1 ) {
         alert("windows xp");
       } else if (version.indexOf("Windows NT 5.2")!=-1 ) {
         alert("windows 2003");
       } else if(version.indexOf("Windows NT 6.0")!=-1){
         alert("windows vista");
       } else if(version.indexOf("Windows NT 6.1")!=-1){
         alert(" windows 7");
       } else if(version.indexOf("Windows NT 6.2")!=-1){
         alert("windows 8");
       } else if(version.indexOf("Windows NT 10.0")!=-1){
         alert("windows 10");
       }