I just read an interesting post by Alex about adoption of Windows Vista. We recently finished a three month research study to discover infection rates on 1,206 medium-sized companies worldwide by performing a malware audit on them. The following are the OS statistics of all the workstations audited. It's interesting to note that Windows Vista is only used in less than 1% of all the workstations audited.

Windows XP Professional SP2 65.94%
Windows 2000 SP4 17.93%
Windows Server 2003 SP1 4.01%
Windows XP Professional SP1 3.91%
Windows 2000 Server SP4 2.46%
Windows Server 2003 SP2 2.24%
Windows Vista 0.92%
Windows 2000 SP3 0.57%
Windows XP Home Edition SP2 0.47%
Windows XP Professional 0.43%
Windows 2000 SP2 0.23%
Windows NT 4.0 Server SP6 0.13%
Windows 98 Second Edition 0.06%
Other 0.70%

Last week I had a series of talks with medium and large companies in Sweden (Stockholm, Göteborg and Malmö) and asked the question of how many workstations used Windows Vista in their networks. The answers are very inline with the stats above.

And finally to correlate against Alex's post, here are the statistics of our main site pandasecurity.lin3sdev.com:

Windows XP 86.1%
Windows Vista 5.9%
Media Center 2005 3.0%
Windows 2000 2.2%
Windows 98 1.2%
Windows ME 0.6%
Windows Server 2003 0.5%
Linux 0.3%
Macintosh 0.1%
Macintosh (iPhone) 0.0%
Media Center 2004 0.0%
Windows NT 0.0%
Windows 95 0.0%
Windows 3.x 0.0%