64-Bit Momentum Surges with Windows 7
 

Are you running a 64-bit edition of Windows 7? There is a high likelihood you are. As of June 2010, we see that 46% of all PCs worldwide running Windows 7 are running a 64-bit edition of Windows 7. That is, nearly half of all PCs running Windows 7 are running 64-bit. Compared to Windows Vista at 3 and a half years after launch, only 11% of PCs running Windows Vista worldwide are running 64-bit. With Windows 7, running a 64-bit OS is becoming the norm.

http://windowsteamblog.com/windows/b...windows-7.aspx