Users running Microsoft's Windows operating system fell below 90 percent market share for the first time in November. Research firm Net Applications Inc. monitors a series of web sites and noted that Microsoft's market share dropped almost a percentage point from the previous month putting its market share at 89.6 percent. Not surprising, Apple Inc's Mac OS X recorded its biggest gain in the past two years to end up with 8.9 percent of the market. Part of the drop can be attributed to the large number of weekends and holidays in November, as Microsoft's market share tends to drop after hours and on weekend due to users logging in from home where there are more users using Macs than at work. One bright spot for Microsoft happened as Vista passed the 20% market share for the first time ending up at 20.45 percent.