All the USB virtual COM (V-COM) drivers support both 32bit(x86) and 64bit(x64).

A type
Supported OSs are
  Windows 7 (32bit)
  Windows 7 (64bit)
  Windows Vista
  Windows Vista x64
  Windows XP
  Windows XP x64
  Windows 2000
  Windows Server 2003
  Windows Server 2003 x64

B type
  Windows Vista
  Windows Vista x64
  Windows XP
  Windows XP x64
  Windows 2000
  Windows Server 2003
  Windows Server 2003 x64
