According to new data from IDC, not only do Windows servers control the most dollar share of the server market, but more servers running Windows were shipped in Q4 of 2010 than in any previous quarter.

From the IDC report:

Microsoft Windows server demand was positively impacted by the x86 server market refresh as hardware revenue increased 16.8% year over year. Quarterly revenue of $6.3 billion for Windows servers represented 42.1% of overall quarterly factory revenue. The 1.5 million server shipments are the highest quarterly total ever reported for Windows servers.

The 42.1% of total revenue figure is an increase from the same quarter in 2009 when Windows servers controlled 41.6% of the dollars spent. Over the same year, Linux servers grew their dollar share while Unix servers dipped.

The first service pack for Windows Server 2008 recently came out, something that might spur its adoption, giving Windows servers potential momentum to continue its current spate of gains.